OnlyOffice Error when trying to connect (Error occurred in the document service: Error while downloading the document file to be converted.)

I’m having quite a few issues with the document server configuration, the same issue have persisted with both, OnlyOffice on Docker and Standalone instance.
When attempting to connect, I get the following
Error when trying to connect (Error occurred in the document service: Error while downloading the document file to be converted.)
The NC logs show the following

Error onlyoffice GetConvertedUri on check error: Error occurred in the document service: Error while downloading the document file to be converted. Error onlyoffice GetConvertedUri on check error: Error occurred in the document service: Error while downloading the document file to be converted. Error PHP implode(): Invalid arguments passed at /var/www/nextcloud/apps/onlyoffice/templates/settings.php#66 Error PHP count(): Parameter must be an array or an object that implements Countable at /var/www/nextcloud/apps/onlyoffice/templates/settings.php#6

In the config.php I’ve specified the following:
'onlyoffice' => array ( 'verify_peer_off' => TRUE, ),
The trusted Domains were configured to point to OnlyOffice document server.

NC instance is running on PHP 7.2. Both servers have trusted Lets Encrypt certs installed on them, tested with wget without any ssl issues. The Document Server is running without any issues.
Some of the errors in apache logs
[Tue Dec 11 18:22:35.272258 2018] [mpm_prefork:notice] [pid 23645] AH00163: Apache/2.4.29 (Ubuntu) OpenSSL/1.1.1 configured -- resuming normal operations [Tue Dec 11 18:22:35.272308 2018] [core:notice] [pid 23645] AH00094: Command line: [Tue [Dec 11 18:22:35.261851 2018] [ssl:warn] [pid 23645] AH01909: '/usr/sbin/apache2' server certificate xxx.zyz does NOT include an ID which matches the server name

I have this same setup & same problem. Running CentOS 7, php 7.2, Apache 2.4, have tried setting my jwt secret and headers to specific values in both OnlyOffice as well as Nextcloud config.php, confirmed access and valid “Lets Encrypt” certs via wget towards both Nextcloud & Onlyoffice. I am running the “standalone” setup, have not tried Docker. Nextcloud 15.0.4, OnlyOffice 5.2.8 - default & local.json seem to be configured correctly.

Getting same error:

Error when trying to connect (Error occurred in the document service: Error while downloading the document file to be converted.)

I have this issue and it’s the last thing preventing my team from using OnlyOffice. :frowning: