I'm sorry for the frustration. I think I'm going to have to ask one of our specialists to contact you on Monday to investigate.  This is unfortunately a rarely seen error that is very generic in nature. There's not a single obvious cause 😞

I do have a few questions that might help me investigate ahead of time:

Is it exactly 25 each time?

Do you have to reboot your machine each time, or just restart ProSeries?

What flavor of ProSeries are you using? Network, Standalone Professional, or Basic?

Did you have this issue with ProSeries 2019?

Can you send me the name of a client file that failed?

Can you look in Help->About, Version Tab and send me your "Device Id"? This will let me look you up on our server to see if there are any clues there.

Can you try to transfer with Microsoft's "Task Manager" running? (Just go to start menu on your desktop and type "task manager").  When you start getting the "Out of Memory" error.. does anything look fishy (highlighted in red or getting close to 100%.. especially CPU or Memory)?

If you'd prefer to wait for our specialist on Monday, that's fine too. This just might give me some clues ahead of time, that will help him or her with the investigation.

Again, sorry for the frustration.Thank you for reaching out, and thanks @Just-Lisa-Now-  for the tag.

Orlando