Hello and welcome back,
Can you please provide your System Information as a private reply? I see you checked Yes for both reverting to the default theme and deactivating all other plugins, but can you please confirm this?
I’ve been testing locally (including tickets) and haven’t encountered this error nor seen any logged bugs of users reporting similar issues, so my first hunch is you’re experiencing a theme and/or plugin. If you haven’t already, please review our Testing for conflicts guide.
Thanks for choosing PRO and I look forward to resolving this with you!