Hi. I'm on Windows 10 pro. I tried in normal and debug (no extension) modes, same problem: Firefox doesn't respond at all if DF is running. As soon as DF is closed, Firefox reacts again. Same result when DF is launched first or Firefox first. It's quite strange as there's no CPU peak, and all the rest seems to run normally.

I'm seeing nearly the same issue, except that in my case it seems to prevent Firefox from starting at all.

Well, I don't know if it's the same as me, but if I launch Firefox while Df beta is already on, Firefox laggs so much that I only have the interface but no page content.

From what I've seen in another thread, the problem might be the combination of DF 11.2b3 + Firefox + Eset antivirus. That's what I have.

That is also the combination that I am running. Hmm.

I'm thinking the Eset combo is the problem. I don't use it and installed 11.2b3 just now and Firefox seems fine.

Any idea when the next Beta is coming out ? I am still having this issue with Firefox,ESET,and Displayfusion.
I did also report this to ESET too, but haven't heard back from them. This makes Firefox impossible to use ( it can take as long as 5 minutes for a page to fully load).

I'm sorry I wasn't more accurate with my statement. I HAVE rolled back to a stable build, and it is working as expected. I meant to say that I can't use the BETA build, because it makes using a browser impossible.
I'll try the next beta build! I am not using a mission critical setup ( my home pc is for gaming mostly), so I don't mind being a beta tester.

Ok, have tried the new beta for a few days and am sad to report that the issue still remains.
It only becomes a problem if you try to download a file or print something out from Firefox. It will slow the system down to a crawl. If I uninstall DisplayFusion, the problem goes away. Or if I use an older version, the problem goes away.

The issue with downloading files is not only with Firefox, I also have the problem with Brave, it just seems worse with Firefox.

Sorry to have taken so long to reply to this post. My PSU shorted out and killed my motherboard , took me a while to get back up and running.

I have not had the chance to do the logging for this, but I can tell you that going into compatability settings , and checking "Disable Titlebar buttons this application only" and "Disable Application Hooks this application only", resolves the issue for me.

I will uncheck those options and run the logger and post it sometime in the next 48 hours.