cannot open project, Says it's running already but unity isn't open

Hi @EliteHedgehog56, Look like the unity process is still running, try open Task Manager find Process tab and kill Unity task.

Another way you could solve this if you haven't already is by following the steps: 1) Open the main project folder 2) Enter the folder 'Temp' 3) Delete the text document 'UnityLockfile'

You should be set. It happens alot with me, and this fixs it. When you close unity normally it deletes the file anyway. If it crashes, it may not delete the file. When you try to load the project, it sees the unity lock file (which is created when ever you open the project) and thinks that another unity must be running it.

I fixed the issue, the temp folder was corrupt so I had to shift everything over to a new folder