I have discovered a serious issue that I believe is caused by DisplayFusion, and it affects my gaming performance.

The FPS drop occurs in all Unreal Engine 5 games (Fortnite, The Finals) and sometimes in CS2, when I minimize (Alt+Tab) and then return to the game.

If I do this many times (minimize and restore), the FPS becomes terrible when moving the mouse — highly stuttering.

Interestingly, if I keep a mouse button pressed and move the mouse, the issue disappears (movement becomes smooth).

This behavior occurs both when the Alt+Tab function in DisplayFusion is disabled and enabled.

Restarting Windows Explorer sometimes helps temporarily.

If I completely close DisplayFusion, the problem disappears entirely.

Recently I also experienced a case where Alt+Tab did not work properly (the game would not switch or lose focus). I have reported this issue before.

Another observation: setting the mouse polling rate to 125 Hz partially mitigates the issue (but the problem still exists over time). At 1000 Hz, the lag is immediately noticeable.

I have recorded a video that clearly shows exactly how things happen. I struggled for years to identify the cause, and now I believe I’ve found the culprit

I noticed the same behavior. While gaming after alt+tabbing a few times the game would start to stutter and frame drop coinciding with mouse movement.

The fix for me was to add the game to compatibility and select 'treat this as a fullscreen application always'

Instant fix, I didn't need to restart the game, DisplayFusion, or windows.
Display Fusion Pro 11.1.1
Windows 11 (24H2) [26100.6584]
Star Citizen 4.3.1 LIVE

Unfortunately this did not help me, the problem still remains

Do you mean Beta 7?

I recorded a video where I encountered three bugs at once:

1. FPS Drop — the drop in performance when minimizing/restoring the game continues; this issue has not been fixed.

2. Alt+Tab broken / flickering — after launching Steam, Alt+Tab inside the game stopped working. I tried both tapping Alt+Tab and holding it down, but it just flickered (you can see it in the video). I don’t know exactly when or how it fails, but at first Alt+Tab worked in the game, then after launching Steam it broke.

3. Tiny windows in the Alt+Tab menu — the previews of open applications become very small or distorted in the Alt+Tab view.

Hello, I tested beta 9. The problem in The finals has really gone away, but I originally wrote that there is such a problem in any game running on the unreal engine 5, is there a universal solution for any game, or will you manually make edits for each game? I can upload a video from another game, for example Arc Raiders or Fortnite or else, where this problem still remains.

Unfortunately, the error solution is still not universal, and this error still persists in ARC raiders. I checked on DisplayFusion Pro on Steam version 12.0. The error still persists, it plays back the same way I recorded videos before. This game is paid, so while I do not know how you will play it, can I help you with this?

The bug has been fixed in Fortnite, thank you. But as I said earlier, this is not a universal solution, the next game on the list is ARC raiders, there is the same problem, maybe there is some other game that I do not know about.

Found this post thanks to ChatGPT Research, I guess AI is good for something for once. Surprised it was displayfusion, thought it was my usual random PC issues.

Noticed this in ARC Raiders the most. After a few raids I need to restart the game or closing DisplayFusion seems to fix it up instantly.

Just update to release build from beta and restarted PC still happening.

Yep here is the attachements. Decide to start pushing my PC a little more as I gamed. I noticed it around 11:37PM when I was back on main menu, was playing the game for like a hour and half or so. Felt like spikes up and down.

Bug started reproducing between 14:11 and 14:13

Hey, just thought I'd chime in as I've been having this issue for a long time when playing Rust. Only just now thanks to a reddit thread I've discovered it's DisplayFusion causing it! I've followed the steps you gave to the previous person and attached the files - hopefully these can help fix this!

Also just realised I hadn't updated to the latest versions from about a week ago, but the problem remains even after updating. I can redo the tests and upload the files again if it's necessary.

Any update on this? its still happening :c
Happy new year !

Yes it does seem that alt tabbing has something to do with it. The issue is completely gone when DisplayFusion is closed.

I have been racking my brain over this issue for a long time! I only recently discovered that it was caused by DisplayFusion, which I have faithfully used for about a decade now.
I'm happy there's some attention to this issue, but until there is an actual universal fix, I cannot use DisplayFusion.

The following games presented issues for me:
Palworld
7 Days to Die
Goblin Cleanup
Crime Scene Cleaner

It's a mix of both UE and Unity.

Hope this helps.

Perhaps you could try the older version. I'm using version 9.X and it works fine.

The topic is marked as resolved even though there is no solution yet, so I am writing this message. It looks like the thread only reopens after I post a message

I can confirm it is still present in the newest beta version. I'm playing The Division 2, and it is unplayable when displayfusion is running (stuttering when moving mouse). Closing displayfusion fixes the stuttering.

Am getting the same issue in Highguard. No alt+tab needed, but it certainly makes it worse
My own testing has deduced it is involving mouse polling rate a possibly it spiking the CPU. Lowering mine from 1000 to 250 makes the stuttering less, and tiny/slow movements only lightly hit the frames. At 1000 its unplayable from first boot, but once DP is closed, flawless

Had the same issue but I didn't think to check with/without displayfusion.

I cannot test it. A critical error appears after the update, the program closes immediately upon startup
DisplayFusion.exe - System Error
A new guard page for the stack cannot be created. --------------------------- OK ---------------------------

Nothing has changed. I’ve recorded a video demonstrating two bugs I previously mentioned.

The first issue is the FPS drop when Alt+Tabbing frequently. it’s still there, and the frame rate continues to tank.

The second is a very annoying bug where I can’t Alt+Tab out of the game. The windows just flicker for a split second, but the switch doesn't happen. If I hold Alt+Tab and then minimize the game using the Windows key to select another window, the Alt+Tab keys get "stuck" and keep rapidly cycling through all open windows.

I’ve included a key overlay at the bottom center of the screen so you can see exactly when I’m pressing the keys.

Apparently the error disappeared when I added Disable Application Hooks in compatibility mode, but I still need to watch, it seems that sometimes there is still a drop in fps, but it quickly returns to normal. At one launch, it was as if this parameter had not been picked up and the fps was still falling. should this setting be done for all games where such a problem appears?

As for the second problem, when it is not possible to switch using alt+tab during the game, I do not know how to reproduce this bug, but now it is not there, sometimes it may appear.

I am also encountering FPS drops when moving my mouse in a game called Dead By Daylight. Consistent 120 FPS, but drops to less than half when moving mouse.

FYI, the workaround of disabling application hooks for a specific program (Dead By Daylight) solves the issue.

I've been having the same stutter issue with Arc Raiders. Every few minutes there's a big frame hiccup. Only way I've found to resolve this is to disable application hooks globally. Disabling the application hooks only for Arc Raiders (pioneergame.exe) in the Compatibility window doesn't seem to work for me, the hiccups still occur.

Only just been able to test so I'm not sure exactly which update fixed it, but it does appear to be fixed for me now in Rust. Before the fix, I would stutter like CRAZY at 1000 Hz polling rate and I'd have to lower it to the minimum possible to be somewhat playable, but even then it was still there. Now I'm testing on 8000 Hz and haven't had the issue at all.

Didn't add any compatibility hooks or change any settings, just updated.

I've been lurking on this topic for a little while since I was having the same issue when I played 7 Days to Die. I just wanted to mention that the latest beta version fixed this issue for me. Hopefully it doean't occur again. Thanks for the quick fix.

I've gone through the steps:
- Updated to the latest DF beta
- Set "Log Level for Hooks" to "1" in Advanced Settings
- Under the Troubleshooting tab I set the log level to "L1: Log Minimal"
- Pressed the "Clear Log" button
- Started playing Arc Raiders
- Noted the timing of the frame hiccups during my game session

I noted the first time around 21:35:27, and after that I noticed it happened around every minute after, shifting ever so slightly later over time.

I was curious about the log itself so looking at the Debug.log text file I noted that this sequence of logs relating to 'tray icon reloading' seemed to line up exactly with the timing I experienced. The duration of the freeze also seems to line up with all the "TrayIcons:NIM_ADD" lines. (see attached debug.png)

EDIT:
I also did a run with applications hooks disabled after that, and it seems this skips these icon reloads (log message reads "[TrayIcons] skipping full enum, taskbar hooks not loaded" in those cases), which also meant I didn't experience the stutter every minute.

I have also been seeing this issue in Rust, and disabling the Hook solved the issue BUT I still have the other issue mentioned, the tiny Alt-Tab thumbnails, has this been addressed?

I think this was maybe a default settings change, as I located the alt-tab thiumbnail,size, which was set to a tiny 100x150, so I just increased the numbers and now they're as big as I had them before.