Error after moving website from subdomain to root domain

Hi, I’ve just moved the website from subdomain to root domain and I’m getting this error:

[01-Feb-2020 11:24:19 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-includes/functions.php on line 6029
[01-Feb-2020 11:24:19 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-admin/includes/misc.php on line 1252
[01-Feb-2020 11:24:19 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-admin/admin-header.php on line 9
[01-Feb-2020 11:25:29 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-includes/http.php on line 494
[01-Feb-2020 11:25:29 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-includes/http.php on line 495
[01-Feb-2020 11:25:29 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-admin/admin-ajax.php on line 27
[01-Feb-2020 11:25:29 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-admin/admin-ajax.php on line 28
[01-Feb-2020 11:25:29 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-includes/functions.php on line 5915
[01-Feb-2020 11:25:29 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-includes/functions.php on line 6029
[01-Feb-2020 11:25:29 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-admin/includes/misc.php on line 1252
[01-Feb-2020 11:25:46 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-includes/http.php on line 494
[01-Feb-2020 11:25:46 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-includes/http.php on line 495
[01-Feb-2020 11:25:46 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-admin/admin-ajax.php on line 27
[01-Feb-2020 11:25:46 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-admin/admin-ajax.php on line 28
[01-Feb-2020 11:25:46 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-includes/functions.php on line 5915
[01-Feb-2020 11:25:46 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-includes/functions.php on line 6029
[01-Feb-2020 11:25:46 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-admin/includes/misc.php on line 1252
[01-Feb-2020 11:25:52 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-includes/functions.php on line 6029
[01-Feb-2020 11:25:52 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-admin/includes/misc.php on line 1252
[01-Feb-2020 11:25:52 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-admin/admin-header.php on line 9
[01-Feb-2020 11:25:55 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-includes/functions.php on line 6029
[01-Feb-2020 11:25:55 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-admin/includes/misc.php on line 1252
[01-Feb-2020 11:25:55 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-admin/admin-header.php on line 9
[01-Feb-2020 11:25:58 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-includes/rest-api/class-wp-rest-server.php on line 1253
[01-Feb-2020 11:25:58 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-includes/rest-api/class-wp-rest-server.php on line 1253
[01-Feb-2020 11:25:58 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-includes/rest-api/class-wp-rest-server.php on line 1253
[01-Feb-2020 11:25:58 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-includes/rest-api/class-wp-rest-server.php on line 1253
[01-Feb-2020 11:25:58 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-includes/rest-api/class-wp-rest-server.php on line 1253
[01-Feb-2020 11:25:58 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-includes/rest-api/class-wp-rest-server.php on line 1253
[01-Feb-2020 11:25:58 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-includes/rest-api/class-wp-rest-server.php on line 1253
[01-Feb-2020 11:25:58 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-includes/rest-api/class-wp-rest-server.php on line 1253
[01-Feb-2020 11:25:58 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-includes/rest-api/class-wp-rest-server.php on line 1277
[01-Feb-2020 11:25:58 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-includes/rest-api/class-wp-rest-server.php on line 1253
[01-Feb-2020 11:25:58 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-includes/rest-api/class-wp-rest-server.php on line 1253
[01-Feb-2020 11:25:58 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-includes/rest-api/class-wp-rest-server.php on line 1253
[01-Feb-2020 11:25:58 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-includes/rest-api/class-wp-rest-server.php on line 1253
[01-Feb-2020 11:25:58 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-includes/rest-api/class-wp-rest-server.php on line 1253
[01-Feb-2020 11:25:58 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-includes/rest-api/class-wp-rest-server.php on line 1253
[01-Feb-2020 11:25:58 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-includes/rest-api/class-wp-rest-server.php on line 1253
[01-Feb-2020 11:25:58 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-includes/rest-api/class-wp-rest-server.php on line 1253
[01-Feb-2020 11:25:58 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-includes/rest-api/class-wp-rest-server.php on line 1253
[01-Feb-2020 11:25:58 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-includes/rest-api/class-wp-rest-server.php on line 1253
[01-Feb-2020 11:25:58 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-includes/rest-api/class-wp-rest-server.php on line 1277
[01-Feb-2020 11:25:58 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-includes/rest-api/class-wp-rest-server.php on line 1253
[01-Feb-2020 11:25:58 UTC] PHP Warning:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-content/plugins/ultimate-maps-by-supsystic/classes/fieldAdapter.php:622) in /data/web/virtuals/159556/virtual/www/domains/yvonne-konig.cz/wp-includes/rest-api/class-wp-rest-server.php on line 1253

The plugin works fine on the website tho. Any idea how can I fix this?

The page I need help with: [log in to see the link]