I've got loads of problems with the Snapshot Pro plugin, on some sites it works fine, but on others, it just won't backup to Google Drive.
I will give you a short summary of what's been done so far
- We've checked if the website passes all requirements, it does now
- we've added some lines to the wp-config.php file, this made the backups finish but there's still a problem with uploading them to Google Drive
- I was asked to create a new webapp for Google Drive in the Developer Console, I did this but the uploading is still not finishing (according to the log it mostly fails somewhere between 60 en 75 percent)
oh and we've enabled error logs for WordPress but yesterday evening there was nothing in there that pointed us in a direction of the problem
Also, we've found that this seems to be related to the backup archive size, as everything works fine if backup includes only core WordPress database tables and no files.