Just to let you know the problem has just popped up again after I migrated my site. I applied the fix from Nigel above... which worked...
So no I idea why the cred latest version 1.8.5 has stopped this working... something to look into perhaps...
It is just really annoying and a waste of time when the same problem keeps coming up and getting fixed then coming back, getting fixed again... as I am sure you would understand.
I'm really interested to find out the cause of the issue. In order to minimize the cause of the issue:
1)
Could you please try to resolve your issue by deactivating all third-party plugins as well as the default theme to check for any possible conflicts with any of the plugins or themes?
2)
Could you please try to deactivate/activate toolset plugins or try to reinstall Toolset plugins.
*** Please make a FULL BACKUP of your database and website.***
I also find that you are using outdated WordPress version. Could you please try to update WordPress to latest version 4.7.2.
=> https://wordpress.org/download/
As I outlined in my support submission the fix Nigel had previously provided has solved my problem for now
You say you are really interested to know the cause of the problem... unfortunately as it works now I don't have time to do what you suggest with my plugins...
I have updated to the latest version of WP and that did not address the issue... and Nigel's fix still works with the new WP
Peter
This ticket is now closed. If you're a Toolset client and need related help, please open a new support ticket.