Bug Bug #1344355: Maximum allowed thread group count is 65535. (Easy to reproduce)

This is still an error I'm seeing in production on Mac hardware. It seems like it might only occur at very high resolutions, but I don't have a huge monitor to test this on.

Below are the specs of the user who experienced this crash. I'm assuming they had a 5k monitor connected. Does HDRP not support resolutions that high on a Mac? Is there some known cause of this I can avoid?

There was some mention of this in a thread from last October, which suggested that it wasn't fully understood, but that at least a leading cause of the issue was being fixed. What is the current status of these crashes?

Spoiler: System specs

DeviceModel
Macmini9,1

DeviceType
Desktop

DPI
186

GraphicsDeviceName
Apple M1

GraphicsDeviceType
Metal

GraphicsDeviceVendor
Apple

GraphicsDeviceVersion
Metal

GraphicsMemorySize
5461

InstallerName
InstallMode
Unknown

IsEditor
False

IsFullScreen
True

OperatingSystem
Mac OS X 10.16.0

OperatingSystemFamily
MacOSX

Orientation
Portrait

Platform
OSXPlayer

QualityLevel
Ultra

ResolutionWidth
5120

ResolutionHeight
2880

ResolutionRefreshRate
60
SystemMemorySize
8192

TargetFrameRate
-1

UnityVersion
2019.4.22f1

Version
0.7.1-beta

Source
Unity

IUserReportingPlatform
UnityUserReportingPlatform

UserReportingClientVersion
2.0

ActiveSceneName
BootstrapperScene

MainCameraName
Main Camera

MainCameraPosition
(0.0, 1.0, -10.0)

MainCameraForward
(0.0, 0.0, 1.0)

ContentLength
36508

Expires
06/17/2021 14:09:48

 

This is still occurring under HDRP 7.6.0.

Here are the specs for the system in question this time:

Code (CSharp):

1. BuildGUID
2. 4f40c894ba055457f9eff5f2a1a831a4
3.  
4. DeviceModel
5. iMac15,1
6.  
7. DeviceType
8. Desktop
9.  
10. DeviceUniqueIdentifier
11. B2CDB67E-D131-5958-911F-F4363AAD9688
12.  
13. DPI
14. 217
15.  
16. GraphicsDeviceName
17. AMD Radeon R9 M290X
18.  
19. GraphicsDeviceType
20. Metal
21.  
22. GraphicsDeviceVendor
23. Apple
24.  
25. GraphicsDeviceVersion
26. Metal
27.  
28. GraphicsMemorySize
29. 2048
30.  
31. InstallerName
32. InstallMode
33. Unknown
34.  
35. IsEditor
36. False
37.  
38. IsFullScreen
39. True
40.  
41. OperatingSystem
42. Mac OS X 10.16.0
43.  
44. OperatingSystemFamily
45. MacOSX
46.  
47. Orientation
48. Portrait
49.  
50. Platform
51. OSXPlayer
52.  
53. QualityLevel
54. Ultra
55.  
56. ResolutionWidth
57. 5120
58.  
59. ResolutionHeight
60. 2880
61.  
62. ResolutionRefreshRate
63. 60
64.  
65. SystemLanguage
66. English
67.  
68. SystemMemorySize
69. 8192
70.  
71. TargetFrameRate
72. -1
73.  
74. UnityVersion
75. 2019.4.22f1
76.  
77. Version
78. 0.7.3-f2-beta-demo
79.  
80. Source
81. Unity
82.  
83. IUserReportingPlatform
84. UnityUserReportingPlatform
85.  
86. UserReportingClientVersion
87. 2.0
88.  
89. ActiveSceneName
90. BootstrapperScene
91.  
92. MainCameraName
93. Main Camera
94.  
95. MainCameraPosition
96. (0.0, 1.0, -10.0)
97.  
98. MainCameraForward
99. (0.0, 0.0, 1.0)
100.  
101. ContentLength
102. 35313
103.  
104. Expires
105. 08/06/2021 04:35:29
106.  
107. GeoCountry
108. US

Is this a known issue? I don't have the hardware this occurred it, it was reported by Unity's crash reporting.

 

I got another crash report today from a user for this same issue. This time, instead of an iMac, it's a MacMini. This is the first time I've seen this occurring on a MacMini.

Details:

Spoiler: Diagnostics

Metadata
BuildGUID
4f40c894ba055457f9eff5f2a1a831a4

DeviceModel
Macmini9,1

DeviceType
Desktop

DeviceUniqueIdentifier
CC71767C-E286-5DDE-B4F1-B163D3B993E5

DPI
217

GraphicsDeviceName
Apple M1

GraphicsDeviceType
Metal

GraphicsDeviceVendor
Apple

GraphicsDeviceVersion
Metal

GraphicsMemorySize
5461

InstallerName


InstallMode
Unknown

IsEditor
False

IsFullScreen
True

OperatingSystem
Mac OS X 10.16.0

OperatingSystemFamily
MacOSX

Orientation
Portrait

Platform
OSXPlayer

QualityLevel
Ultra

ResolutionWidth
5120

ResolutionHeight
2880

ResolutionRefreshRate
60

SystemLanguage
English

SystemMemorySize
8192

TargetFrameRate
-1

UnityVersion
2019.4.22f1

Version
0.7.3-f2-beta-demo

Source
Unity

IUserReportingPlatform
UnityUserReportingPlatform

UserReportingClientVersion
2.0

ActiveSceneName
BootstrapperScene

MainCameraName
Main Camera

MainCameraPosition
(0.0, 1.0, -10.0)

MainCameraForward
(0.0, 0.0, 1.0)

ContentLength
32269

Expires
09/20/2021 13:51:34

Again, this is a crash that occurs the first frame that game is active.

I've formally reported this as bug #1344355. However, I'm confident that this bug will never make it past QA, since QA pretty much insists that a repro project be attached to any bug issues before they glance at it. In this case, these are crashes I only see occurring on Mac hardware at 5K resolutions. I can't try to reproduce this since I don't have a 5K display to test on.

@SebLagarde , is this already a known issue, so I can stop worrying about it? Is it based on some known configuration I can change?

 

I wouldn't have expected that setting the resolution higher than the display's max resolution was even an option. But that's interesting, and I'll try it out.

I'm on 7.6 now, so we'll see if that helps.

I also added some code to my game, for now, that caps resolution at somewhere between 4 and 5k, just to avoid having people stumble upon this. But since I don't have a 5K Mac display, I don't know if/when I'll be able to confirm if that actually matters.

 

I received another crash report on this today, on a build running HDRP 7.6.0. So, whatever changes were recently made to address the '65535' issue still have some failure modes.

In my previous post I mentioned I added some code to hopefully avoid this error, by forcing a resolution change at startup if the resolution was higher than ~4K. Unfortunately, that doesn't work. This error occurs on frame 0 of the first scene I load. The first scene is empty, aside from a canvas with a single black image in it. With the error occurring on frame 0, it crashes before any of my own code even runs, which means my resolution change code doesn't run before the crash.

 

I reported this as bug #1344355, and it's very simple to reproduce. Basically, create a brand new HDRP project. Go to the Game View, and create a new Resolution preset at 5120x2880 resolution. Now create a new scene, and open it. You should start seeing the error in the console:

"Thread group count is above the maximum allowed limit. Maximum allowed thread group count is 65535."

From here, you can enter and exit play mode to see the error repeated several times each time you do this.

This just seems to be an issue with HDRP now behaving properly at very high screen resolutions. The huge problem with this is that Macs often default to 5K resolution, so Mac users can easily get this error to occur before anything can even be done to attempt to lower the screen resolution.

It's worth noting that I've tried the same thing on 2021.2 Beta, and the error does not occur. But it's very easy to reproduce under the latest version of 2019.4 LTS.

 

QA responded that this is being tracked: https://issuetracker.unity3d.com/is...build-crashes-when-using-a-high-resolution-5k

Hoping for a backport to HDRP 7 under 2019.4 LTS, to avoid having iMac users instantly getting errors upon launching my game.