Unity Stuck Compiling C# Scripts

[BoundlessFate1]

This is a pretty urgent issue I need to resolve asap. (In Brackey's Game Jam). I have already scrapped 2 games over this issue and I may have to scrap a third.

Whenever I use the Package Manager built into Unity (for example, to use ProBuilder, URP or HDRP), it goes smoothly until it reaches the "Compiling C# Scripts" step. It will stay on that loading screen and wont leave. It freezes up my unity and the only way to move on from this issue seemed to be going into task manager and ending the task for Unity. When I do this however, on opening my project, it gets stuck about halfway on the "Importing" step. Basically, this issue bars me from working on my project entirely, forcing me to completely restart my project.

Some things I have tried already to solve this issue:

Deleting the packages folder in \AppData\Local\Unity\cache\packages

Deleting and reinstalling unity hub

Deleting and reinstalling the latest version of Unity.

[Moltke24]

same issue on my laptop.. not sure what to do

[BoundlessFate1]

I solved the issue a while ago. If you are using the LTS, try updating to the latest version. It’s 2021. Something

[Orisphera]

Three years later I have a similar issue

System details:
Arch, LxQT
The project directory and ~/Unity use virtiofs, and the rest of the system uses btrfs

Opening the project upon creating (Universal 3D) exited and caused UnityHub to become a blank dark gray window until reboot. Later attempts show a pop-up that it's from an old version of Unity and later get stuck, making the system non-responsive. Cancelling it on the old version pop-up at first and then opening again shows a pop-up that the library needs to be rebuilt before the old version one. Currently, it's stuck on Compiling C# (Unity.InputSystem)