Delete and Stop process in forms monitor is not working.
There was a process that causes this issue. I manually went into the database and update task status. This fixed the issue.
Thank you All!
Stop and delete instance doesn't work even for a simple process such as a message start event follow up a user task?
Please open a support case with your Solution Provider and provide the Forms version and video that can illustrate the issue, we need more information in order to troubleshooting your issue.
Are you getting error messages or anything like that?
I haven't see the specific issue of not being able to stop or delete instances, but whenever I'm finding stuff in LFForms is getting stuck and not processing as expected - the first thing I try is going to the LFForms server and restarting the "Laserfiche Forms Routing Service", that solves a lot of the issues that arise.
We did try to restart that service and it appears to not solve the issue. No Error Message
And everything else is working normally, forms are submitting, tasks are assigning to users, etc.?
those seems to be working.
Hopefully someone else has an idea what else you can try, because I'm stumped. 
Sorry, and good luck.