What a pain in the *** is pdf conversion for me.
Finally, I had it al working for about one year. Now I upgraded to Moodle 3.6 and it's all bad again.
unoconv - doesn't work (hosting on WHM panel)
Google: stopped working. Deleted everything, tried to get a new service going but the docs on this are outdated. Google Developer Console looks totally different and I can't find out how to set it up anymore.
Microsoft: this ons worked best in the past, but also stopped working. Also deleted it, set it up again but still the same error:
Error code: conversionfailed
$a contents: Array
[statusmessage] => The file was not uploaded to Microsoft OneDrive.
line 494 of /lib/setuplib.php: moodle_exception thrown
line 223 of /files/converter/onedrive/classes/converter.php: call to print_error()
line 52 of /files/converter/onedrive/test.php: call to fileconverter_onedrive\converter->serve_test_document()