How to reproduce:
1. Open the “WebGLAsyncGPUReadbackTest“ project
2. Make sure that the build is set to “WebGL” (File > Build Settings > “WebGL” > “Switch Platform”)
3. Build And Run
4. In the Player open the browser console
5. Wait for 1 minute
6. Observe the browser console

Expected result: No allocation errors are thrown
Actual result: The “Could not allocate memory” error is thrown

Reproduced with: 2021.3.32f1, 2022.3.14f1, 2023.2.1f1, 2023.3.0a13
Not reproducible with: 2023.3.0a15
Fixed in: 2023.3.0a14

Reproduced on: Windows 10 (by reporter), Windows 11
Not reproducible on: No other environment tested

Browser reproduced on: Firefox, Chrome, Edge

Notes:
1. Not reproducible in Editor
2. The error is constantly being thrown to the browser console
3. On the Firefox browser the errors are not thrown to the console but instead after some time the Player throws an error and stops rendering → Full error provided in internal comments
4. Not reproducible on the Edge browser in 2021.3.32f1
5. The browser console can be opened by different shortcuts. These shortcuts are also different for each browser. The default shortcuts can be located here https://docs.unity3d.com/Manual/webgl-debugging.html

Error thrown to the browser console:

{noformat}Could not allocate memory: System out of memory!
Trying to allocate: 3686400B with 16 alignment. MemoryLabel: TempOverflow
Allocation happened at: Line:62 in
Memory overview
ALLOC_TEMP_TLS ] used: 7372800B used: 2120291187B | peak: 2120291607B | reserved: 2120520745B
ALLOC_TEMP_JOB_1_FRAME ] used: 0B used: 0B | peak: 0B | reserved: 0B
ALLOC_TEMP_JOB_4_FRAMES (JobTemp) ] used: 0B used: 106B | peak: 0B | reserved: 524288B
[ ALLOC_GFX ] used: 3747131B | peak: 3747131B | reserved: 3749392B{noformat}