Solution for Onlyoffice not working with Nextcloud version over 19

Please open File Explorer and go to Docker folder > Nextcloud>config to find the config.php file.

Then, download it.

Edit the config.php by using Notepad.

Add below to the file and save the file.

'allow_local_remote_servers' => true,

Upload the revised file back to the config folder and it should be working fine again.