How to reproduce:
1. Open the attached "1269771.zip" project
2. Build Asset Bundles for Windows Standalone using WIndows > Asset Bundle Browser (follow photo steps below)
3. Make sure IL2CPP backend is selected in the project settings
4. Build and run a Development Build
5. Click on the button "Load" two times

Expected Behavior: The bundle is loaded and unloaded without errors
Actual Behavior: The bundle is not unloaded after the first load and runtime console throws exceptions (image attached in the edits)

Reproducible with(editor versions): 2019.4.19f1, 2020.2.3f1, 2021.1.0b4
Could not test with: 2018.4 due to broken packages, 2021.2 - the editor crashes while loading

Reproducible with(Package versions): 1.7.0

Note:
- This does not reproduce on Mono
- Does not reproduce in the editor