Hi ​@Nahid - The error message you are receiving is quite generic. As an immediate troubleshoot I could suggest would be to review the Timeframes for that process, especially if you have a reciprocating reference (e.g. a linked process that links back to the existing processes) and remove any extremely large timeframes from the calculation. 

If the issue has been persisting I would advice you to raise this with support@nintex.com

Hi ​@EvgeniosE, My colleague checked the timeframes for the process, and it appeared there is no timeframe has been set. She has also contacted the Nintex support, and they issued a case number.  I am ProMaster and couldn’t resolve the issue. I see there are a couple of copies of the process in the system that it won't let me either archive / delete them. I am wondering if the issue is due to that.

Copies of the process shouldn’t affect it as the way they are created the processes are completely independent (what matters is not the name of the process, but rather the unique reference to it in the URL). A quick troubleshooting you could try is to go to Admin > Manage Groups > Locate the relevant process and manually move it to another group. Press Save and repeat to move the process back to its original Group location. In rare occasions processes can be corrupted and this is an in-product way to force a reset. If the issue persists the best chance for resolution would be through Nintex Support. 

Thanks ​@EvgeniosE, We have just tried your suggestion above and it didn’t work. we even tried to make a copy and try the steps but that didn’t work either. We get an error message that says “Bad Request”, not sure what that means?

A “Bad Request” could cover a number of errors/issues. There is a chance the underlying process definition was somehow corrupted. The best way forward is to escalate that with Nintex Support.

My colleague has escalated it with Nintex Support and the developer weeks ago but no action has been taken so far. She approached me as I am a ProMaster, but unfortunately, I haven’t been able to fix the issue. Thanks for your help anyway.