Reproduction steps:
1. Open the user's attached project
2. Inspect Console

Expected result: No "CS8377" errors are thrown
Actual result: "CS8377: the type struct must be a non-nullable value type, along with all fields at any level of nesting, in order to use it as parameter 'T' in the generic type or method" error is thrown

Reproducible with: 2019.4.9f1, 2020.1.4f1, 2020.2.0b1
Couldn't test with 2018.4 (ECS is not supported)
Reproducible with package versions: 0.11.1-preview.4
Couldn't test with newer package versions (project errors after upgrade due to API changes)

Note: on 2020.2.0b1, different errors are thrown ("error CS0121: The call is ambiguous between the following methods or properties")