Flickering graphics caused by launcher version or integrated GPU? [SOLVED]

If it is (has happened a couple of times to me) you still see the app in the task bar. It does nothing once the game .exe is up.

I do believe there’s some confusion between the game update itself (which gets done first, and happens every time the launcher says “gotta load an update”), and an update to the launcher itself (which is noticeable as it calls a Windows installer pop-up, and seldom happens). In this case, Zwift released a game update (including a long list of mods, such as a hud-off mode), and a launcher update. As @shooj indicated, the functions of the launcher are quite limited, and as the name implies, have nothing to do with how the game performs.

In this case, there was a game update (for Win10, to 1.12.0 (1.0.67624) (April 21 2021)), and a launcher update (to whatever version, not sure if they track that separately).

No confusion here, the launcher has an impact on game performance and stability. Don’t ask me how and why, but it does. See the videos above, try it yourself.

And it’s nothing to do with the game update, aside from this is the first time the launcher update is being forced. This actual launcher isn’t even new, it’s been around for months.

So you stepped back to the previous game .exe, and tested with two configs where the only differences were ZwiftLauncher.exe and the DLLs included in the launcher update?

Yes. It takes seconds to switch between the two.

And I’ve tried it on a clean install too, in case you were going to ask. :wink:

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So clean install to pre-1.0.67624, old launcher, tests ok, add new launcher, still with pre-1.0.67624, and the rendering is screwed? I’m not questioning your abilities (you appear to clearly know what you’re doing), I’m just puzzled (as you are).

If this launcher version has been around for a while, presumably the issues would have been visible by users who installed it?

The videos in reply 8 of this thread I took several months ago. The videos in reply 15 I took this evening. Different game versions, same issue with launchers. Up to and including 1.0.50 it was fine. Versions 1.0.51 and 1.0.52 (current) cause issues, irrespective of the game version. That’s why I’ve been using - both for myself and when building for others - and actively recommending the old launcher for yonks now. See here: New launcher (1.0.51) causing stutter on Windows systems

The reason this thread exists is because the launcher never used to update itself, but now it does.

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The one oddball thing in the launcher install is the presence of an updated “Patcher.dll” - no clue what’s in there, but it’s possible the game .exe makes use of that dll.

Purely speculative. You’d have to recover the old dll to test that hypothesis.

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Yeah same Dave, I’ve had a huge drop in frames since the update.

Please look into it zwift!!

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Yeah that’s one file I didn’t try when messing about earlier (I tried PresentationFramework.dll and PresentationCore.dll, no joy) because why would the patcher… well exactly. Will give it a go though.

To be honest the flickering stuff I’m less bothered about personally because it only happens at very high frame rates; higher than I will be using. The stutter is awful IMO and appears all the time. However stutter is virtually impossible to capture, you’ve got to see it in person and some people don’t notice or care. I’m using adaptive sync so it stands out immediately to me. The flicker is easy to see and demonstrates a) that there are issues and b) that the launcher does impact the game somehow. Both need sorting out before we get to the point at which the launcher cannot be rolled back.


I mean a launcher that doesn’t use IE would be nice. It could even be updated to be an app fitting of the 2020 decade at least?


Updated my Zwift PC yesterday to latest game version.
Launcher didn’t update itself, it’s still 1.0.44.
I first installed Zwift in Nov. 2018 and never reinstalled.

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Interesting. From 1.0.50 it asks to update the launcher every time you hit Let’s Go. I’ve got 1.0.44 kicking around somewhere, I’ll have to check it.

Well, I didn’t ride yesterday, I just updated the game and shut down the PC.
I didn’t hit Let’s Go.
On my way to the basement to test…

So, yeah, after hitting Let’s ride the launcher gets updated to 1.0.52.
Did a quick Just Watch and analyzed the log file with zwiftalizer.
All looks good with my i5-3470, 8GB, GTX960

Frame rates aren’t the issue tbh. Are you in full screen mode or windowed?

Windowed mode.
1080p. Ultra Profile.

Thought so. :wink:

You probably wouldn’t see any of the flickering demonstrated above even with vsync off because Windows itself (DWM) enforces it when you’re in windowed mode. And IMO the game has always been a lot less smooth in windowed mode anyway. YMMV

I suspect this is why not everyone is seeing what I am, since I run full screen mode exclusively. And with vsync off for testing it’ll run at 150fps in 4K given the right camera view.

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After a little playing around I have identified what I believe to be the problematic file of several that change when you update the launcher beyond version 1.0.50. Updating that one file on an otherwise perfectly functioning install to the newer version (as updated by the current version of Zwiftsetup.exe) causes all the performance and graphical issues I have highlighted in this thread and the previous one. Swapping back that one file to the older version resolves it immediately. Swapping every other updated file in this manner does not have any impact, just this particular one.

Unfortunately it does not work in reverse, in that copying the old file into a new install does not resolve the issues me and others are seeing. In fact it presumably breaks some integrity check since you have to bypass the launcher altogether from that point on to get into the game.

So I believe it has to be something relating to this file and how the game and launcher interact with it. I’ve been blaming ‘the launcher’ but it’s probably to do with the files that come with the more recent installers instead.

Please let me know who I should contact directly about this, since replicating my testing requires some digging around in the Zwift system files* which probably isn’t appropriate for posting here.

*Not hacking anything here, don’t worry. :wink:


Are there other folks on this thread besides @Mike_Rowe1 who are noticing this?

I fully trust you’re seeing what you are @Dave_ZPCMR, but I’m wondering if other things specific to your setup are contributing to this issue.

Do you happen to have a second Windows machine to compare against? Completely different display, display cable and separate everything from your primary machine? For troubleshooting purposes, can you reproduce this with other variables in your graphics chain?

Yeah as noted in my previous thread where I listed some of the builds at that time, I’ve probably seen this on half a dozen different systems by now, in every combo I can realistically do. Different graphics cards (tiers, brands and models), displays and cables. Completely clean installs each time I’ve tried it (since 1.0.51), the game just performs poorly compared to what I’m used to so I roll the launcher back, which rewrites these files and we’re back to normal. Lovely and smooth motion, with no flickering at high frame rates. Done three fresh installs tonight on my main rig to test this copying and pasting strategy with the files, moving each and every one back and forth to try find what I now believe is the culprit. :rofl: