Unity freezes when selecting objects in project window

As the title says, I am having an issue since I recently imported an asset called space station from "Many Worlds" developer found at https://assetstore.unity.com/packages/3d/environments/sci-fi/space-station-31047. Whenever I select an object in my project window, Unity freezes for 1-2 minutes or more and I get the following error at the end of the freeze:

Assertion failed: Assertion failed on expression: 'userId < staticRenderers.size()'
UnityEngine.GUIUtilityrocessEvent(Int32, IntPtr)

I have tried googling this and have come up with nothing. It has brought my development to a halt. I have tried reinstalling Unity and downgrading the version a bit to Unity 2017.2.0 but this did not help.

Any ideas as to what this error means? Bare in mind I know nothing about coding. I am running the latest version 2017.3.of3

 

Anybody seen anything like this or know what it means?

 

Haven't seen this issue, but some common sense advice would be to remove the asset from your project and see if that resolves the issue. If so then I would contact the asset developer about it. If not then it may have just been coincidental that you are encountering this issue at the same time you imported this asset.

 

Well, I had attempted the library delete method, which just corrupted it. I then tried reimporting all assets, which had no effect. Then out of sheer random guessing, I tried clearing my occlusion culling data, and the error was gone...I have rebaked at a higher "Smallest Occluder" count, as the original was set to 0.5, now on 5 and the problem no longer exists. I honestly have no idea what this means lol but it is no longer an issue.

 

I had the same error and spent days to fix it, and clearing Occlusion Culling data fixed the issue. Thank you very much!