I had already attempted the suggested update on one of my servers, with no luck. As of this morning, it was still throwing warnings, and I have rebooted and cleared the cache since applying the update.
So, to ensure I hadn’t missed something I added variants. In all, here are the entries that I added:
- quform_sessions (recommended)
I’m not sure which of these worked, but one of these entries helped. I copied these settings to several of my sites, and they all appear to have stopped throwing the PHP warning reported earlier.
NOTE: I had to purge all W3TC caches for this to work, but it worked almost immediately after that.
If you can review which variants might have worked and confirm that it appears to be the additional of “quform_session_” or “quform_sessions_”. It would be really helpful to update the page you linked to.
Thanks for the continued support!