Zulip-desktop: App bright white flashing and flickering while scrolling

[eligang]

---

• Operating System:
  
  
  
  • [ ] Windows
  
  
  • [ ] Linux/Ubutnu
  
  
  • [x] macOS Sierra
  
  
• Clear steps to reproduce the issue:
  While scrolling through messages in a stream topic, there's recurrent bright white flashes in a flickering streak across the screen. This does not happen while using Zulip in a browser.
  The app is also using a significant amount of CPU usage while open.
• Relevant error messages and/or screenshots:

[akashnimare]

@eligang can attach a screenshot/gif here?

[eligang]

@akashnimare here you are. thanks

[warsaw]

I see exactly the same thing with Zulip 1.9.0 on macOS 10.13.4 (High Sierra).

[abhigyank]

@eligang Can you reproduce this flicker in the normal white display(non night mode) too?

[warsaw]

@abhigyank It does not seem to happen for me in the normal (non-night mode) display.

[akashnimare]

Interesting. Never seen this kind of bug, let me try to reproduce this.

[akashnimare]

@eligang, @warsaw I can't reproduce this.

Can you folks reproduce this issue on https://chat.zulip.org/ server?

[timabbott]

Howdy @warsaw! Can you check whether you get the same issue if you do the same scrolling in the Zulip webapp in Chrome? That'd be helpful for isolating whether it's a webapp or Electron bug.

(Also, are you using the latest 1.9.0 release of the Electron app? I assume so, since the Python community usage of Zulip is new, but wanted to confirm)

[warsaw]

@timabbott Hi! I cannot reproduce this with the Zulip webapp in Chrome in night mode. Only the macOS desktop client in night mode AFAICT.

[timabbott]

Good to know. This feels like a browser bug (basically in upstream electron). @akashnimare I think the next thing to try is to download the version of Chromium that Electron is on and reproduce that there?

[eligang]

@timabbott I actually am having some flashy blips in the regular non-night mode of the Zulip Electron app (yes, the 1.9.0 release) on Mac as well, but not nearly as bad or frequently consistent flickering as shown in night mode (although it also might just be less obvious in this scheme). Whether or not it's on the high contrast mode doesn't seem to make a difference either.

[akashnimare]

I think this might be a caching issue. Can you folks clear the application data using the following option from setting page -

[timabbott]

I don't really see a story for how this would be a caching issue. But I guess it's pretty hard to come up with a good theory for why this is happening that isn't something weird:

• It doesn't reproduce with Chrome for the same users
• It doesn't reproduce for other users with the desktop app.

[warsaw]

Resetting the app data does not fix the problem for me, although as I'm watching it now, the flashing is more apparent when scrolling quickly.

[akashnimare]

Here is my observation (macOS 10.13.2 High Sierra)

• Works as expected in night mode and normal mode (chat.zulip.org server).
• Same result on python's Zulip server.

@warsaw let me update to macOS 10.13.4 and check if I can reproduce this.

[akashnimare]

Updated to macOS 10.13.5 Beta but no luck reproducing the issue.
This might be related - https://bugs.chromium.org/p/chromium/issues/detail?id=470669

[eligang]

This does sound like a similar problem, but is it related when using the Zulip desktop app in Mac OS? I don't tend to have this issue while using the web app in Chrome (or Safari), so it seems to be specifically something with the macOS app- and I'm only on 10.12.6 Sierra.

[shidarin]

I also have this problem.

https://gfycat.com/charmingpeskychinesecrocodilelizard

OSX 10.12.6
Zulip Desktop App 1.9.0

Not present in the web app.

Occurs on both CZO and our internal Zulip instance (which is on 1.8). I've been having this issue since before the 1.8 upgrade though.

It's very obvious on the dark theme. I've switched to the light theme and think I've seen it once or twice. I will attempt to record it.

[akashnimare]

Can you folks reproduce this bug in the latest release which is v2.0.0 ?

[warsaw]

The macOS version for download is still 1.9.0 and there doesn't seem to be a menu option to download and install a new version.

[akashnimare]

@warsaw the app should auto-update itself in a while. App will show following popup -

Feel free to comment if it doesn't show this in a while.

[timabbott]

@akashnimare maybe worth opening a separate issue for adding a "check for updates" option on the screen showing the version? I think that would be a good idea for this sort of test-a-new-release situation.

[akashnimare]

Yeah, I had thought to do so but somehow missed it. Generally, desktop app adds this option in the file menu item -

[eligang]

I've updated to the 2.0.0 version and no change- still the bright white flashing. I am also on an internal Zulip server instance at our org.

I recall this being the case before the 18.0 app version as well, but it either became worse/ more frequent or just more obviously headache-inducing apparent with the night mode setting, which would otherwise be my preferred view. But it also does happen in the regular non-night mode too.

[shidarin]

Experienced this issue again today on 2.0 on both CZO and a self hosted instance (both running the 1.8.1-rc) it was on both white and dark themes, but reset itself when I changed apps to start a screen capture. FYI, changing apps does seem to reset it frequently. Hard to capture.

[akashnimare]

@shidarin okay, I'll be releasing a new beta release tomorrow which uses the updated chromium version and I'm hoping this error will be sorted after that.

[timabbott]

Yeah, this certainly feels like a browser bug.

[abhigyank]

A new beta v2.2.0-beta has been released, this contains an update to the electron version which uses an updated chromium version, which hopefully should solve this issue. So please give this beta a try. To upgrade to this version, you need to check the Get beta updates option from app settings. Or manually download from here .

[warsaw]

Indeed. A quick test with 2.2.0-beta appears to have fixed the problem. I'll keep an eye on it, but so far so good! Thanks.

[akashnimare]

@warsaw awesome. @shidarin, @eligang can you folks also confirm if this works for you?

[eligang]

@akashnimare Just updated to the beta version. Yes, this is great- MUCH smoother now when scrolling and the flashing issues seems to be completely resolved (even in night mode)! Thank you :)

[akashnimare]

@eligang good to know. Feel free to reopen the issue if you see something like this in future!

[shidarin]

I've also updated to the beta and have also not hit this issue yet.