How to reproduce:
1. Open the attached “IN-137899” project
2. In the top menu bar, select “Build” → “Select Configuration”
3. In the “BuilderWindow”, select “aftershock_debug”, set the “Platform”: iOS and check the “Fat Build” option
4. Click the “Full Build (Code+Bundle)” button
5. Once the build is finished, go to System Settings → Privacy and Security and allow “AkSoundEngine”
6. Open the “Unity-iPhone.xcodeworkspace“ file in Xcode
7. Build to a device
8. On the loading screen, tap with four fingers to open the Debug menu (If the window suggests restartin, click the button and then repeat this step)
9. Select the "NUE Lite (SKIP NUE HERE)" → "Mark NUE Complete"
10. On the loading screen, tap with four fingers to open the Debug menu again
11. Select “Server Selector” → “Go to Server Selector” → “Design”
12. After the loading screen, tap with four fingers to re-open the Debug menu
13. Select “Unlock All Heroes”
14. On the left side of the screen, select “Roster”
15. Find the “Blue Marvel” character (it may help to sort the list alphabetically)
16. In the Blue Marvel window, click the blue mask icon located under the character
17. In Blue Marvel hero window, click on the unchecked blue box
18. Observe the crash

Actual result: Selecting a skin causes a crash
Expected result: The skin selects without crashing

Reproducible with: 2022.3.76f1
Could not test with: 2022.2.0a1, 6000.0.74f1, 6000.3.14f1, 6000.4.5f1, 6000.5.0b6, 6000.6.0a4 (multiple unresolvable custom package errors)

Reproducible on: macOS 15.3.2 (24D81) (M1 Max)
Not reproducible on: No other environment tested

Reproducible with these devices:
VLNQA00346, iPad Air (4th generation), (MYFR2HC/A), CPU: Apple A14 Bionic, OS: 26.2.1
VLNQA00626, iPhone 16 (MYE73QN/A), CPU: Apple A18 Pro, OS: 18.6.2
VLNQA00535, iPhone XS (MT9F2ET/A), CPU: Apple A12 Bionic, OS: 17.6.1
VLNQA00491, iPhone 14 Pro (MQ083PX/A), CPU: Apple A16 Bionic, OS: 16.0
Samsung Galaxy A52 (Tested by the reporter)
Samsung Tab S8 Ultra (Tested by the reporter)
Google Pixel 9 Pro XL (Tested by the reporter)

First few lines of the stack trace:
frame #0: 0x00000002474b80cc libsystem_kernel.dylib`__pthread_kill + 8
frame #1: 0x00000001f96ee810 libsystem_pthread.dylib`pthread_kill + 268
frame #2: 0x00000001a87409e8 libsystem_c.dylib`raise + 32
frame #3: 0x00000001240fc3e0 UnityFramework`DebugStringToFilePostprocessedStacktrace(DebugStringToFileData const&) + 1196
frame #4: 0x00000001240fc850 UnityFramework`DebugStringToFile(DebugStringToFileData const&) + 676
frame #5: 0x00000001238d06b0 UnityFramework`CachedReader::OutOfBoundsError(unsigned long, unsigned long) + 252

Note: According to the user, the crash also occurs in Unity 6