Is this occurring randomly or at a specific spot in the script?
Have you monitored where your Memory usage is at during the process? (if UiStudio or UiRobot get over 2mb used, you will have problems)
Have you checked how much C: drive storage space is available?
Is this run on a local Laptop or a server/VM and have you tried another machine?
How many user ids are connected to the server while it is running? Try signing them out.
Also, check the Windows Event Viewer which will show you all the errors which you can reference.
Maybe those questions will help pinpoint a hardware or software issue if that’s the case.
Actually, as I’m typing this, I remember I am having the same problem with one of our processes, and after several days with UiPath Support we ended up concluding that it was caused by server performance and with too many user ids connected. The same process works on another server just fine. I still think it’s something UiPath is doing but server performance is something to atleast consider.