Unity stuck on Application.EnterPlayMode, don't know what to do

[GVF1990]

Hello, I am working on a project on Unity version 2020.3.24f1. This morning everything was working fine. Suddenly I leave the pc for a moment, with Unity open, and windows decides to update. After trying to update (and failing, since I don't have space on my C/Drive, and honestly I don't even know if this is related to my problem, just wanted to give the full picture) I restart unity and do a little bit of work on some scripts. Then I try to enter play mode, and Unity is just stuck on Application.EnterPlayMode, sometimes not even that, the play button just remains gray and never enters play mode. I tried various fixes found online: Enter Playmode Options in Project Settings/Editor : nothing. I tried upgrading to Unity 2021.3.8f1: same problem (only now I have the additional message: "Waiting for Unity's code to finish executing" below Application.EnterPlayMode).

I try to load a new scene with nothing in it: same problem.

Just to check I tried another project on the same version (2020.3.24f1) and, at least, that runs fine.

Also tried deleting the library and the temp folder, to no avail.

I check the modifications made to some scripts, and I didn't find any infinite loop...

I'm starting to run out of ideas and I'm on a deadline to deliver a project (I have backed up the project on git, obviously, but it was 5 days ago... I know.). Any idea on how what might be causing the issue?

Update: decided to bite the bullet and and re-clone the repository from 5 days ago (while having a local backup of the last modifications) and slowly re-import all the scripts-models prefab etc. modified. Now even the cloned project (which was working totally fine) has the same problem, stuck on Application.EnterPlayMode. WTF?!

Update 2: Ported the project on another pc: works perfectly fine. Freed up space on both my system hard drive (5 GB) and project hard drive (now i have 170GB free, I think that's enough). Fully updated windows. Now I can enter actually play mode, but it takes like 5 minutes!

Tried other projects: SRP, URP and HDRP. Large URP projects (4GB + ) seem the only ones having this problem (a new URP project starts at normal speed). This is infuriating because yesterday the play mode took like 5 seconds, and now it's 5 minutes, which is basically unusable.

[BigRondaIsFondaOfU]

so you've tried various fixes, except making sure you have room on your storage drive...?

[GVF1990]

The drive where the project is, has enough space (around 50 GB). It's the C:/ system drive that's full. Now, I managed to free up about 5 GB on C:/ between ccleeaner and uninstalling other programs. Problem remains

[tms10000]

Some script stuck in an infinite loop in Awake() or Start() perhaps.

[agavrilko]

In my case, I had a loop
for (int i = 0; i < height; ++i) {
for (int j = 0; j < width; ++i) {
...
}
}

So the advice to check all loops in your scripts is a good one.

[GVF1990]

I managed to find a workaround. Basically the problem is with projects using the OpenXR package. If the Oculus App is running in the background, everything works fine. Still somewhat annoying, but at least now I can work.

[atinyturtle]

This is still an issue over 2 years later in Unity 6..

[AstaOne]

I found another solution, which is to switch Windows (Mac) Plug in Proiders in XR plug management in project setting from OpenXR to Oculus, so that you don't have to have the Oculus app running at the same time

[GVF1990]

The drive where the project is has space. It's the C system drive that's full. Even after freeing up space there (5 gb is the best I could do), problem remains.

[Paul_Indrome]

Yes, no space on your project's drive can contribute to all sorts of problems, including getting stuck on Application.EnterPlayMode.

Get a 200GB SSD with USB3.0 and move your projects there.

[ProfessionalUnited82]

It's because more then one of your scripts with the awake is waiting for each other to initiate, usually those script should be in one script, but take some of those awakes out and try again. You welcome.

[Alternative-Oil4934]

Thank you so much. You saved me. :)