How to reproduce:
1. Open user's attached project from "Project.zip"
2. Create a new 3D template project
3. Navigate to "File" > "Build Settings ..." > select any platform > "Switch Platform"

Reproducible with: 2020.2.0b12, 2020.2.0b13, 2020.2.0b14, 2020.2.0f1, 2020.2.1f1
Not reproducible with: 2018.4.30f1, 2019.4.17f1, 2020.1.17f1, 2020.2.0b11, 2021.1.0b1

First lines of stacktrace:
0x00007FFE0A224FFF (mono-2.0-bdwgc) [c:\build\output\unity-technologies\mono\mono\mini\mini-generic-sharing.c:2917] mono_method_is_generic_sharable_full
0x00007FFE0A13D3C7 (mono-2.0-bdwgc) [c:\build\output\unity-technologies\mono\mono\mini\mini-runtime.c:2051] mono_jit_compile_method_with_opt
0x00007FFE0A13DD16 (mono-2.0-bdwgc) [c:\build\output\unity-technologies\mono\mono\mini\mini-runtime.c:2692] mono_jit_runtime_invoke
0x00007FFE0A0C2902 (mono-2.0-bdwgc) [c:\build\output\unity-technologies\mono\mono\metadata\object.c:2921] do_runtime_invoke
0x00007FFE0A0CB95F (mono-2.0-bdwgc) [c:\build\output\unity-technologies\mono\mono\metadata\object.c:2968] mono_runtime_invoke
0x00007FF792FD5D94 (Unity) scripting_method_invoke

Notes:
1. Reproducible only after opening the specific Project from the user.
2. Deleting the Library folder from the projects directory fixes issue.