White Screen of death – frontend

Hi,

We’ll get on our homepage http://www.ostdeutschlandglaubt.de a white screen of death. I deactivated the plugins, but the issue stays. When I change the theme, the white screen of death disappears.

I’ve got some debugs on debug.log:

[27-Nov-2020 14:48:44 UTC] PHP Deprecated: Function create_function() is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php on line 53
[27-Nov-2020 14:48:46 UTC] PHP Fatal error: Allowed memory size of 536870912 bytes exhausted (tried to allocate 14217856 bytes) in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/wp-db.php on line 1999
[27-Nov-2020 14:49:49 UTC] PHP Deprecated: Function create_function() is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php on line 53
[27-Nov-2020 14:49:49 UTC] PHP Deprecated: Function create_function() is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php on line 66
[27-Nov-2020 14:49:49 UTC] PHP Deprecated: add_option_whitelist ist seit Version 5.5.0 veraltet! Benutze stattdessen add_allowed_options(). in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/functions.php on line 4777
[27-Nov-2020 14:49:49 UTC] PHP Deprecated: Array and string offset access syntax with curly braces is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/codestyling-localization/includes/idna_convert.class.php on line 421
[27-Nov-2020 14:49:49 UTC] PHP Deprecated: Array and string offset access syntax with curly braces is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/codestyling-localization/includes/idna_convert.class.php on line 435
[27-Nov-2020 14:49:49 UTC] PHP Deprecated: Array and string offset access syntax with curly braces is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/codestyling-localization/includes/idna_convert.class.php on line 826
[27-Nov-2020 14:49:49 UTC] PHP Deprecated: Array and string offset access syntax with curly braces is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/codestyling-localization/includes/idna_convert.class.php on line 957
[27-Nov-2020 14:49:49 UTC] PHP Deprecated: Function create_function() is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php on line 53
[27-Nov-2020 14:49:49 UTC] PHP Notice: ob_end_clean(): failed to delete buffer. No buffer to delete in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php on line 191
[27-Nov-2020 14:49:49 UTC] PHP Deprecated: get_settings is deprecated since version 2.1.0! Use get_option() instead. in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/functions.php on line 4777
[27-Nov-2020 14:49:49 UTC] PHP Deprecated: get_currentuserinfo is deprecated since version 4.5.0! Use wp_get_current_user() instead. in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/functions.php on line 4777
[27-Nov-2020 14:49:59 UTC] PHP Deprecated: Function create_function() is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php on line 53
[27-Nov-2020 14:49:59 UTC] PHP Deprecated: Function create_function() is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php on line 66
[27-Nov-2020 14:49:59 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php:53) in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/functions.php on line 6274
[27-Nov-2020 14:49:59 UTC] PHP Deprecated: add_option_whitelist ist seit Version 5.5.0 veraltet! Benutze stattdessen add_allowed_options(). in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/functions.php on line 4777
[27-Nov-2020 14:49:59 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php:53) in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-admin/includes/misc.php on line 1310
[27-Nov-2020 14:50:00 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php:53) in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/pluggable.php on line 1296
[27-Nov-2020 14:50:00 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php:53) in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/pluggable.php on line 1299
[27-Nov-2020 14:50:06 UTC] PHP Deprecated: Function create_function() is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php on line 53
[27-Nov-2020 14:50:06 UTC] PHP Deprecated: Function create_function() is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php on line 66
[27-Nov-2020 14:50:06 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php:53) in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/functions.php on line 6274
[27-Nov-2020 14:50:07 UTC] PHP Deprecated: add_option_whitelist ist seit Version 5.5.0 veraltet! Benutze stattdessen add_allowed_options(). in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/functions.php on line 4777
[27-Nov-2020 14:50:07 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php:53) in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-admin/includes/misc.php on line 1310
[27-Nov-2020 14:50:07 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php:53) in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/pluggable.php on line 1296
[27-Nov-2020 14:50:07 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php:53) in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/pluggable.php on line 1299
[27-Nov-2020 14:50:14 UTC] PHP Deprecated: Function create_function() is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php on line 53
[27-Nov-2020 14:50:14 UTC] PHP Deprecated: Function create_function() is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php on line 66
[27-Nov-2020 14:50:14 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php:53) in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/functions.php on line 6274
[27-Nov-2020 14:50:14 UTC] PHP Deprecated: add_option_whitelist ist seit Version 5.5.0 veraltet! Benutze stattdessen add_allowed_options(). in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/functions.php on line 4777
[27-Nov-2020 14:50:14 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php:53) in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-admin/includes/misc.php on line 1310
[27-Nov-2020 14:50:14 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php:53) in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/pluggable.php on line 1296
[27-Nov-2020 14:50:14 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php:53) in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/pluggable.php on line 1299
[27-Nov-2020 14:50:20 UTC] PHP Deprecated: Function create_function() is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php on line 53
[27-Nov-2020 14:50:20 UTC] PHP Deprecated: Function create_function() is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php on line 66
[27-Nov-2020 14:50:20 UTC] PHP Deprecated: add_option_whitelist ist seit Version 5.5.0 veraltet! Benutze stattdessen add_allowed_options(). in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/functions.php on line 4777
[27-Nov-2020 14:50:27 UTC] PHP Deprecated: Function create_function() is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php on line 53
[27-Nov-2020 14:50:27 UTC] PHP Deprecated: Function create_function() is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php on line 66
[27-Nov-2020 14:50:28 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php:53) in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/functions.php on line 6274
[27-Nov-2020 14:50:29 UTC] PHP Deprecated: add_option_whitelist ist seit Version 5.5.0 veraltet! Benutze stattdessen add_allowed_options(). in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/functions.php on line 4777
[27-Nov-2020 14:50:29 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php:53) in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-admin/includes/misc.php on line 1310
[27-Nov-2020 14:50:29 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php:53) in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/pluggable.php on line 1296
[27-Nov-2020 14:50:29 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php:53) in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/pluggable.php on line 1299
[27-Nov-2020 14:51:12 UTC] PHP Deprecated: Function create_function() is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php on line 53
[27-Nov-2020 14:51:12 UTC] PHP Deprecated: Function create_function() is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php on line 66
[27-Nov-2020 14:51:12 UTC] PHP Deprecated: add_option_whitelist ist seit Version 5.5.0 veraltet! Benutze stattdessen add_allowed_options(). in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/functions.php on line 4777
[27-Nov-2020 14:51:12 UTC] PHP Deprecated: Array and string offset access syntax with curly braces is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/codestyling-localization/includes/idna_convert.class.php on line 421
[27-Nov-2020 14:51:12 UTC] PHP Deprecated: Array and string offset access syntax with curly braces is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/codestyling-localization/includes/idna_convert.class.php on line 435
[27-Nov-2020 14:51:12 UTC] PHP Deprecated: Array and string offset access syntax with curly braces is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/codestyling-localization/includes/idna_convert.class.php on line 826
[27-Nov-2020 14:51:12 UTC] PHP Deprecated: Array and string offset access syntax with curly braces is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/codestyling-localization/includes/idna_convert.class.php on line 957
[27-Nov-2020 14:51:12 UTC] PHP Deprecated: Function create_function() is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php on line 53
[27-Nov-2020 14:51:12 UTC] PHP Notice: ob_end_clean(): failed to delete buffer. No buffer to delete in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php on line 191
[27-Nov-2020 14:51:12 UTC] PHP Deprecated: get_settings is deprecated since version 2.1.0! Use get_option() instead. in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/functions.php on line 4777
[27-Nov-2020 14:51:12 UTC] PHP Deprecated: get_currentuserinfo is deprecated since version 4.5.0! Use wp_get_current_user() instead. in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/functions.php on line 4777
[27-Nov-2020 14:51:18 UTC] PHP Deprecated: Function create_function() is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php on line 53
[27-Nov-2020 14:51:18 UTC] PHP Deprecated: Function create_function() is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php on line 66
[27-Nov-2020 14:51:18 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php:53) in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/functions.php on line 6274
[27-Nov-2020 14:51:18 UTC] PHP Deprecated: add_option_whitelist ist seit Version 5.5.0 veraltet! Benutze stattdessen add_allowed_options(). in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/functions.php on line 4777
[27-Nov-2020 14:51:18 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php:53) in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-admin/includes/misc.php on line 1310
[27-Nov-2020 14:51:18 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php:53) in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/pluggable.php on line 1296
[27-Nov-2020 14:51:18 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php:53) in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/pluggable.php on line 1299
[27-Nov-2020 14:51:23 UTC] PHP Deprecated: Function create_function() is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php on line 53
[27-Nov-2020 14:51:23 UTC] PHP Deprecated: Function create_function() is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php on line 66
[27-Nov-2020 14:51:23 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php:53) in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/functions.php on line 6274
[27-Nov-2020 14:51:23 UTC] PHP Deprecated: add_option_whitelist ist seit Version 5.5.0 veraltet! Benutze stattdessen add_allowed_options(). in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/functions.php on line 4777
[27-Nov-2020 14:51:23 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php:53) in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-admin/includes/misc.php on line 1310
[27-Nov-2020 14:51:24 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php:53) in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/pluggable.php on line 1296
[27-Nov-2020 14:51:24 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php:53) in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/pluggable.php on line 1299
[27-Nov-2020 14:51:27 UTC] PHP Deprecated: Function create_function() is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php on line 53
[27-Nov-2020 14:51:27 UTC] PHP Deprecated: Function create_function() is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php on line 66
[27-Nov-2020 14:51:27 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php:53) in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/functions.php on line 6274
[27-Nov-2020 14:51:27 UTC] PHP Deprecated: add_option_whitelist ist seit Version 5.5.0 veraltet! Benutze stattdessen add_allowed_options(). in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/functions.php on line 4777
[27-Nov-2020 14:51:27 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php:53) in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-admin/includes/misc.php on line 1310
[27-Nov-2020 14:51:29 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php:53) in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-admin/admin-header.php on line 9
[27-Nov-2020 14:51:35 UTC] PHP Deprecated: Function create_function() is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php on line 53
[27-Nov-2020 14:51:35 UTC] PHP Deprecated: Function create_function() is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php on line 66
[27-Nov-2020 14:51:35 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php:53) in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/functions.php on line 6274
[27-Nov-2020 14:51:35 UTC] PHP Deprecated: add_option_whitelist ist seit Version 5.5.0 veraltet! Benutze stattdessen add_allowed_options(). in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/functions.php on line 4777
[27-Nov-2020 14:51:35 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php:53) in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-admin/includes/misc.php on line 1310
[27-Nov-2020 14:51:36 UTC] PHP Warning: Cannot modify header information – headers already sent by (output started at /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php:53) in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-admin/admin-header.php on line 9
[27-Nov-2020 14:51:52 UTC] PHP Deprecated: Function create_function() is deprecated in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-content/plugins/maintenance-mode/maintenance-mode.php on line 53
[27-Nov-2020 14:51:53 UTC] PHP Fatal error: Allowed memory size of 536870912 bytes exhausted (tried to allocate 14217856 bytes) in /www/htdocs/w00f9ca4/ostdeutschlandglaubt.de/wp-includes/wp-db.php on line 1999

I’ve downloaded the theme und reinstalled it today, it doesn’t works. Maybe you could help me.