Are the users seeing any message at all when this happens?

We had one customer with a weird intermittent error that I eventually solved but it took daylight savings to figure out. The user would enter a transaction and get a SQL disconnect message. This user was often the only one impacted. What we discovered was that it happened at roughly the same time each day when she came back from lunch. No windows logs recorded any issues. When we changed the clocks in the spring, the time frame of the error moved ahead one hour as well.

So I ran a ping in a batch file that recorded the ping to the database server results every ten seconds.

On Wednesday, at about 12:30pm, or 1:30pm after "leap forward", the database connection would be severed on VM #5 (they had six VMs for load balancing).

Sage won't tolerate a break in the database connection for more than about 30 seconds. If you have left a window open and the database connection is cut from 'underneath it' then you'll see an error when you make the screen go to the database. If you just close the screen and open it again you'll be a refreshed DB connection.

What was happening was that the mid-day image backup of VM#5 was failing and that caused the timeout. Because this was happening "outside" of the server, nothing showed up in any of the logs we had access to. We finally got the attention of IT with specific proof that this VM, during this time frame every week, would be unable to ping the database server for about five minutes. They saw their VM logs shows problems at that time. (This had been going on for months and months - IT company was fired since they couldn't be bothered to look since it was a 'software issue'.)

So - my point is, do the users see an error message when the PO/OE screen closed up? Is so, does it indicate that there was a SQL client communication error? It's very rare for windows to close without any dying last message. And when that happens - I like to make sure that the video card drivers are up to date. I've seen updating those fix weird crashing issues.

Good luck!

Thanks Django. 

The users are not getting any error.  The screen just closes on them.  I have asked them to document the problem with more detail so we can see if there is anything common.