I suspect this appeared after you updated to WordPress 4.8.3. That update has introduced several issues with CRED, although I haven't seen this particular error message reported before.
So I would like to take a copy of your site so we can identify exactly what circumstances are creating it, if that's okay.
I will mark your next reply as private so that I can get log-in credentials from you—you may want to create a temporary admin user for me to use that you can later delete. And be sure to have a current backup of your site, even though I don't intend to make any changes other than to temporarily add a backup plugin to take a snapshot of the site.
@Nicola, it would be helpful to take a look at your site, too, to see what it has in common, but I'll need you to open a separate thread to be able to get details from you. You can assign the thread directly to me, or if you find you cannot, mention me in the thread and I will look out for it.
The developers are already aware of this issue, and it will be fixed in a CRED update that we are about to publish that will fix several issues related to WP 4.8.3.
When you see the update please try again and let me know if you still experience problems.
Hi Nigel,
I'm experiencing a similar but not identical issue after the WP types plugins update. All cred forms are not loading. Any idea when the bugfix is released?
I should also add that CRED forms are now inaccessible from the backend as well. I can get to the list of forms but when clicking on a form to edit it, nothing happens.
The CRED 1.9.2.1 update was a hotfix to address a small number of specific issues that arose with the WP 4.8.3 update, and was not a full version update.
That means that any open CRED errata are still open, and the fixes they contain need to be reapplied if they are relevant to your site.
If you still have issues then, Garen, please update here, and @others, please open new threads to report your specific issue, so that we can get further details about your specific installations.
Finally, let me apologise for the inconvenience and frustrations you are experiencing, we are aiming to identify and fix these issues as quickly as possible.
