Have a client running Sage 100 2017 standard.

Client runs a few V/I jobs from the Job Select menu.  Problem occurs when the click the job and try running it.  The screen closes abruptly.

Then, when they try again, the job is locked and does not show on the Job Select menu.

Have to unlock the job in Import Job Maintenance to fix the problem.

What's causing the problem, and how do I prevent it from happening in the future?