Xcode 12.3 iOS 14.3 simulators Yellow Dock / yellow translucent issues

Question

Today I downloaded the release of Xcode 12.3, and I went running the iOS 14.3 simulators and it seems like there is a graphic glitch that all translucent views are yellow, dock included.

I redownloaded iOS 14.2 and those seem fine. It just seems really odd. I've submitted feedback, but I was curious if anyone else has seen this?

I'm on macOS v10.15.7 (Catalina) and am curious of if it's just Catalina or also macOS v11 (Big Sur).

Same here: Xcode 12.3, Big Sur, 15" 2018 MBP. Could you please mention your feedback identifier so that we can corroborate the issue to Apple? — Clément Cardonnel, Dec 15 '20 at 07:16
This is only happening on my iPhone 12 Pro simulator. Just tested on iPhone 12 Mini, which works fine! :-) — ThomasCle, Dec 15 '20 at 09:14
Seen on Catalina 10.15.7 today as well for iPhone 11 iOS 14.3 simulator — jhm, Dec 15 '20 at 09:20
Same problem here: Big Sur 11.1, Xcode Version 12.3 (12C33), iMac Retina 5K 27" 2019. — Hardy, Dec 21 '20 at 07:20
Could you check with simctl to see if the yellow shows up in a screenshot as well? Then can you use the OS screenshot feature to trigger an iOS screenshot into the camera roll and report it that shows the same yellow? — russbishop, Dec 22 '20 at 06:29
@user1046037 Is that confirmed? I wasn't seeing the bug so I can't check the fix. :) — matt, Jan 28 '21 at 19:15
I was experiencing it earlier and now it doesn’t happen for iOS simulator. I think the release note also mentions that it is fixed for iOS simulator — user1046037, Jan 29 '21 at 14:59

zrfrank · Answer 1 · 2021-01-26T06:56:09.983

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Xcode 12.4 RC has announced fix.

iOS simulated devices no longer display an incorrect yellow tint in translucent UI elements. Certain GPUs may continue to display the tint with some tvOS simulators. (71203015)

I think it is a bug related to the discrete GPU.

In addition, this bug causes the background of the on-screen keyboard to be almost RGB(0,0,0). Experienced on MBP 2017 with Catalina.

Workaround I - Using integrated GPU

In the simulator, set menu File → GPU Selection → Prefer Integrated GPU to work around this bug.
Restart the simulator.

This was tested on a MacBook Pro with Catalina and Big Sur. As comments suggest that it won't work on iMac.

Workaround II - Reduce transparency

In the simulated device (e.g. iPhone), Settings → Accessibility → Display & Text Size → turn on Reduce Transparency.

Notice that it can only reduce the previous 'solid' yellow to 'fairly light'.

I find this workaround, as the discrete GPU can be used, is more suitable for testing the UI logic than the previous solution.

This was tested on a MacBook Pro with Catalina. Might work on iMac.

edited Jan 26 '21 at 06:56

answered Dec 15 '20 at 10:47

zrfrank

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This fixes the problem for every start of the simulator. – Matoz Dec 15 '20 at 10:51
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Thanks! It works for me (macOS 11.1, MacBook Pro 2016) but makes the simulator miserably slow when performing basic UI animations. – Darrarski Dec 15 '20 at 11:20
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Restart your simulator after making this change to see the effects – Chris Chute Dec 15 '20 at 22:24
This works on Catalina, just remember to restart the simulator. No need to unplug anything. Best – jQN Dec 18 '20 at 14:03
makes it super slow btw. – Adam Dec 19 '20 at 21:46
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The workaround does not work for me. (Big Sur 11.1, Xcode Version 12.3 (12C33), iMac Retina 5K 27" 2019.) – Hardy Dec 21 '20 at 07:22
This solution also works in the simulator within Xcode's SwiftUI view preview. However I had to restart Xcode to get it to notice the new GPU setting. – Mark Knopper Dec 21 '20 at 22:16
To be honest, I think the best "workaround", during development, is probably mentally ignore the 'transparent so yellow' and train the brain so that it's been treated as transparent. Happy debuging! – zrfrank Dec 23 '20 at 07:42
Reducing transparency helps a lot on my iMac but not completely. Does anyone know what the right fix is for the iMac? – GroovinChip Dec 25 '20 at 02:11
Not working with eGPU + Big Sur + MBP '19 – Massimo Pavanel Dec 28 '20 at 08:47
The first workaround worked for me. I'm using Catalina (10.15.7) – Jobert Jan 07 '21 at 06:16
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The "Workaround I - Using integrated GPU" worked with me (on Xcode 12.3, Big Sur 11.0.1, MBP2019), thanks. – Ricardo Barroso Jan 07 '21 at 19:38
This did not work for me either, on an 27" iMac 5K Late 2015 running Catalina 10.15.7. I downloaded the older 14.2 simulator to use while this is still an issue, which works fine. – Valdimar Jan 08 '21 at 13:15
should be accepted answer. Don't forget to reload the simulator, guys – Zaporozhchenko Oleksandr Jan 27 '21 at 08:05
Thanks for reporting the Xcode 12.4 fix; have we confirmed that it really does fix it? – matt Jan 28 '21 at 19:15
@matt confirm on mbp2017 with Catalina. – zrfrank Jan 29 '21 at 06:58
@zrfrank Yay! Glad to hear it – matt Jan 29 '21 at 07:28
this works but the bug wasn't fixed in xcode 12.4 for me – bze12 Apr 16 '21 at 01:34

score 15 · Answer 2 · edited Dec 16 '20 at 01:22

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Are you using a MacBook Pro? I had the same bug.

I solved in the following ways.

Step 1: Unplug all cables, including the charging cable
Step 2: Restart the iOS simulator

edited Dec 16 '20 at 01:22

Peter Mortensen

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answered Dec 15 '20 at 06:53

Kenji Wada

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This did work but the issue comes back on starting the Simulator next time when the power cable is connected. – Matoz Dec 15 '20 at 10:30
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In light of @zrfrank answer, I guess that unplugging the MacBook makes it switch to its integrated GPU so this can indeed work. It didn't work for me because I had "Prefer Discrete GPU" checked. – Clément Cardonnel Dec 15 '20 at 15:01
Works, as long as you don't plug the power back in and restart the simulator again. So I guess unplugging the power cable just make the simulator switch to integrated gpu, and back again to discrete, once the power is back. – d4Rk Dec 16 '20 at 09:37
I suggest you try the @zrfrank "Workaround I - Using integrated GPU", it worked just fine on my MBP 2019 (Xcode 12.3, Big Sur 11.0.1) even if I then restart the Simulator again. – Ricardo Barroso Jan 07 '21 at 19:42

score 6 · Answer 3 · edited Dec 31 '20 at 08:01

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Best way around it (what I've done), is to download the 14.2 Simulator pack from within Xcode.

Open Xcode->Preferences
Tap Components
Tap the 14.2 Simulator pack and Xcode is going to start installing it.

It's a workaround till they fix that miserable error.

edited Dec 31 '20 at 08:01

Mario Zigliotto

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answered Dec 19 '20 at 22:38

Adam

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After trying the above mentioned workarounds, this one fixed the problem. For some reason, I previously had a "iPad Pro (12.9-inch) (4th generation) (14.3) in the scheme selector, although just 14.1 and 14.2 simulators were installed. Therefore, this must be changed as well. – Hardy Dec 21 '20 at 07:54
However, the SwiftUI previews are not fixed by that, still showing strange things... – Hardy Dec 21 '20 at 07:59
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And as every new Xcode there are hundreds of issues to fix before I can continue my work. Thanks Apple!!! BTW none of the mentioned workarounds fixed it... – Sal Dec 24 '20 at 16:57

score 5 · Answer 4 · answered Dec 28 '20 at 08:27

It is Xcode 12.3 bug! you can see that sometimes in the code interface builder too:

It is not critical but If you really care about it, download and use the previous Xcode from here

Nothe that you can't build for iOS 14.3 if you choose to use Xcode 12.2.

More description

Xcode always have unknown issues at the release point. Some of them are critical like this with 54K views! and some are not like this issue with about 5K views in only 13 days. My suggestion is to always have 2 Xcodes at the same time until you are sure about Xcode bugs!

I had Xcode 12.3 and Version 12.5 solved the problem! – CGN Jun 09 '21 at 12:52 — CGN, Jun 09 '21 at 12:52

score 2 · Answer 5 · answered Jan 21 '21 at 18:02

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Happened to me as well, while I was charging my MacBook Pro 2016. I closed my Xcode, disconnected my charger from the Macbook and run it again. The problem was fixed.

answered Jan 21 '21 at 18:02

Dakata

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score 0 · Answer 6 · answered Jan 18 '21 at 08:23

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One thing to point out/confirm: Seems the issue is limited to the simulator. The issue does not persist when sideloading the project to iPhone.

answered Jan 18 '21 at 08:23

Merid

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Xcode 12.3 iOS 14.3 simulators Yellow Dock / yellow translucent issues

6 Answers6

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