https://www.displayfusion.com/Discussions/RSS/?TopicID=019adecf-6dda-74a3-a175-4f337598e769 DisplayFusion RSS: Firefox Becomes Extremely Slow with DisplayFusion 12 Beta 8 Mon, 06 Apr 2026 04:50:54 GMT en hourly 1 https://www.displayfusion.com/Discussions/RSS/?TopicID=019adecf-6dda-74a3-a175-4f337598e769 https://www.displayfusion.com/Discussions/View/firefox-becomes-extremely-slow-with-displayfusion-12-beta-8/?ID=019adecf-6dda-74a3-a175-4f337598e769#12 Wed, 07 Jan 2026 08:39:25 GMT Binary Fortress Software https://www.displayfusion.com/Discussions/View/firefox-becomes-extremely-slow-with-displayfusion-12-beta-8/?ID=019adecf-6dda-74a3-a175-4f337598e769#12 DisplayFusion After reinstalling DisplayFusion, the issue is no longer occurring.
I’m not sure whether the reinstall fixed it or if something was updated on ESET’s side.
For now, I’ll continue to monitor the situation as it is. ]]> https://www.displayfusion.com/Discussions/View/firefox-becomes-extremely-slow-with-displayfusion-12-beta-8/?ID=019adecf-6dda-74a3-a175-4f337598e769#11 Tue, 30 Dec 2025 16:13:56 GMT Binary Fortress Software https://www.displayfusion.com/Discussions/View/firefox-becomes-extremely-slow-with-displayfusion-12-beta-8/?ID=019adecf-6dda-74a3-a175-4f337598e769#11 DisplayFusion Could you do the following to send me some more information about the application window that's having this issue?

• Install one of our other apps, Window Inspector: https://www.binaryfortress.com/windowinspector (it's free)
• Open the affected application
• Open Window Inspector
• Hover over the affected window with your mouse so that the affected window's info shows in the Window Inspector window
• Press Ctrl + Shift + F1 to freeze the timer in Window Inspector
• Press Ctrl + Shift + F2 to save the info from Window Inspector to a file
• Send me the file from the previous step

]]> https://www.displayfusion.com/Discussions/View/firefox-becomes-extremely-slow-with-displayfusion-12-beta-8/?ID=019adecf-6dda-74a3-a175-4f337598e769#10 Mon, 29 Dec 2025 16:11:46 GMT Binary Fortress Software https://www.displayfusion.com/Discussions/View/firefox-becomes-extremely-slow-with-displayfusion-12-beta-8/?ID=019adecf-6dda-74a3-a175-4f337598e769#10 DisplayFusion Not only Firefox has performance issues. Quotes in MetaTrader 5 freeze every few seconds. Additionally, the icon for the “Status Window” in Hard Disk Sentinel no longer jumps to the taskbar on the monitor where that window is located. That’s all I’ve noticed. The last version that worked correctly was 11.2 (beta 7). ]]> https://www.displayfusion.com/Discussions/View/firefox-becomes-extremely-slow-with-displayfusion-12-beta-8/?ID=019adecf-6dda-74a3-a175-4f337598e769#9 Mon, 29 Dec 2025 06:52:22 GMT Binary Fortress Software https://www.displayfusion.com/Discussions/View/firefox-becomes-extremely-slow-with-displayfusion-12-beta-8/?ID=019adecf-6dda-74a3-a175-4f337598e769#9 DisplayFusion I updated to DisplayFusion 12.0.1, but there still seem to be compatibility issues with Firefox and ESET.
When using Firefox and selecting an image in a form (for example, when uploading an image via a browser), it takes an abnormally long time only when DisplayFusion is running.
The environment is Windows 11 Pro 25H2 (build 26200.7462). ]]> https://www.displayfusion.com/Discussions/View/firefox-becomes-extremely-slow-with-displayfusion-12-beta-8/?ID=019adecf-6dda-74a3-a175-4f337598e769#8 Thu, 25 Dec 2025 17:27:16 GMT Binary Fortress Software https://www.displayfusion.com/Discussions/View/firefox-becomes-extremely-slow-with-displayfusion-12-beta-8/?ID=019adecf-6dda-74a3-a175-4f337598e769#8 DisplayFusion Yes, I would also like to report DisplayFusion taking up to 90%+ CPU usage when a large number of windows are open. I had around 15 VLC windows open (not playing) and close to 50 IrfanView windows. Windows 10 handled it fine, but DisplayFusion made my PC slow to a crawl. ]]> https://www.displayfusion.com/Discussions/View/firefox-becomes-extremely-slow-with-displayfusion-12-beta-8/?ID=019adecf-6dda-74a3-a175-4f337598e769#7 Thu, 18 Dec 2025 14:45:17 GMT Binary Fortress Software https://www.displayfusion.com/Discussions/View/firefox-becomes-extremely-slow-with-displayfusion-12-beta-8/?ID=019adecf-6dda-74a3-a175-4f337598e769#7 DisplayFusion @UnderPL1 Are you on Windows 10 as well? ]]> https://www.displayfusion.com/Discussions/View/firefox-becomes-extremely-slow-with-displayfusion-12-beta-8/?ID=019adecf-6dda-74a3-a175-4f337598e769#6 Thu, 18 Dec 2025 00:07:45 GMT Binary Fortress Software https://www.displayfusion.com/Discussions/View/firefox-becomes-extremely-slow-with-displayfusion-12-beta-8/?ID=019adecf-6dda-74a3-a175-4f337598e769#6 DisplayFusion Same issue here: Task Manager shows DisplayFusion using up to 20% CPU for no reason on Beta 10. ]]> https://www.displayfusion.com/Discussions/View/firefox-becomes-extremely-slow-with-displayfusion-12-beta-8/?ID=019adecf-6dda-74a3-a175-4f337598e769#5 Wed, 17 Dec 2025 16:02:30 GMT Binary Fortress Software https://www.displayfusion.com/Discussions/View/firefox-becomes-extremely-slow-with-displayfusion-12-beta-8/?ID=019adecf-6dda-74a3-a175-4f337598e769#5 DisplayFusion Seems I have the same issue. I tried latest Beta (9) of DF but it did not change anything. If I exit DF, then FF seems to work fine. Else it takes several seconds (5 or more) before a page is loaded.

FF: 146.0
Eset: Small Business Security 19.0.14.0
Windows 10: 22H2 19045.6691 ]]> https://www.displayfusion.com/Discussions/View/firefox-becomes-extremely-slow-with-displayfusion-12-beta-8/?ID=019adecf-6dda-74a3-a175-4f337598e769#4 Thu, 11 Dec 2025 13:31:34 GMT Binary Fortress Software https://www.displayfusion.com/Discussions/View/firefox-becomes-extremely-slow-with-displayfusion-12-beta-8/?ID=019adecf-6dda-74a3-a175-4f337598e769#4 DisplayFusion Glad to hear ]]> https://www.displayfusion.com/Discussions/View/firefox-becomes-extremely-slow-with-displayfusion-12-beta-8/?ID=019adecf-6dda-74a3-a175-4f337598e769#3 Thu, 11 Dec 2025 01:45:08 GMT Binary Fortress Software https://www.displayfusion.com/Discussions/View/firefox-becomes-extremely-slow-with-displayfusion-12-beta-8/?ID=019adecf-6dda-74a3-a175-4f337598e769#3 DisplayFusion It seems the issue has been resolved with Beta 9. Thank you. ]]> https://www.displayfusion.com/Discussions/View/firefox-becomes-extremely-slow-with-displayfusion-12-beta-8/?ID=019adecf-6dda-74a3-a175-4f337598e769#2 Wed, 03 Dec 2025 14:42:34 GMT Binary Fortress Software https://www.displayfusion.com/Discussions/View/firefox-becomes-extremely-slow-with-displayfusion-12-beta-8/?ID=019adecf-6dda-74a3-a175-4f337598e769#2 DisplayFusion I was able to reproduce something similar here, we'll take a look into it and see what we find.

Thanks! ]]> https://www.displayfusion.com/Discussions/View/firefox-becomes-extremely-slow-with-displayfusion-12-beta-8/?ID=019adecf-6dda-74a3-a175-4f337598e769 Tue, 02 Dec 2025 11:25:27 GMT Binary Fortress Software https://www.displayfusion.com/Discussions/View/firefox-becomes-extremely-slow-with-displayfusion-12-beta-8/?ID=019adecf-6dda-74a3-a175-4f337598e769 DisplayFusion After updating to DisplayFusion 12 Beta 8, I noticed that Firefox has become extremely slow, especially with network access.
- Up to Beta 7, there were no issues.
- With Beta 8, Firefox’s network performance is heavily impacted.
- If I exit DisplayFusion’s background process, Firefox runs normally without any problems.
Has anyone else experienced this behavior?
In the past, there was a known compatibility issue between DisplayFusion and ESET, and I’m wondering if this might be a similar case.
Additional Information:
- ESET version: 19.0.14.0
- Windows version: 11 25H2 (26200.7309 Preview)
- Firefox version: 145.0.2
- Disabling ESET protection while running DisplayFusion did not resolve the issue.
Any feedback or confirmation from others encountering the same problem would be appreciated. ]]>