Good day,

We've been using Dosbox SVN MB6 to run an ancient program for years. This seems to be the only release I've ever been able to tinker with and get to print reports correctly in. This is across multiple clients still holding on to DOS based programs. I also recognize that this release of SVN MB6 is ancient. I tried recent releases of Dosbox-X, but it always broke at printing. One client needs Printfil to get it to do what they need on top of this, another uses DOSPRN, but this client that's impacted dumps output to a laser printer that I think emulates Epson control code correctly, and it works/prints in the correct font/size, etc.

Today I received a call that the program was working on Monday and not today. When I connected and looked, the resolution was turned down very low, and the Dosbox launch screen with text about CPU cycles was on the screen. The program's batch file to launch seemed hung pre-loading screen. It seems to hang here until I Ctrl-Alt-Delete and open Task Manager, which then gets the app to open. The mouse moves in the app, but you can't click anything. Then you have to click the X which causes DOS to panic and crash with an error from the program.

I looked at recent Microsoft Updates, and to test uninstalled KB5121003 today, and much to my surprise it resolved the issue. It seems that KB5121003 was installed right after KB5120708 on 08/25/2026. Since this is a security update, it would be my preference to not keep this uninstalled, so I'm appealing to people that work with the depths of Dosbox development more than I. Is there a way I can trace this issue and isolate what might be causing it? There's so many options in Dosbox that I'm sure it may be something that could be worked around.

If there's a better place to ask this question on the internet, please refer me. I've read these forums over the years, but I think this is my first post.

Cheers,
-pd