Prefab related bugs and crashes on upgrading project in 2018.3

I get a load of errors saying:
PPtr cast failed when dereferencing! Casting from PrefabInstance to Prefab!
If i take something like my camera object and pull it into the project folder it crashes Unity.
If i delete all the then greyed out components with (Removed) on them and little circle icons with a dash, then it does not crash but gives the below error:
Asset import did not unload metadata path. This will leak memory. File a bug with repro steps please. (Assets/Visuals/Camera/Main Camera.prefab)

More info:

1. I can open another small Android project no problem.
2. I opened this project on another computer and had the same issue.
3. I see there are others commenting about the "PPtr cast failed when dereferencing". I assume my other issues are related.

 

Thanks for the reply. Depending how long it is before the fix, i might just wait. Can you give a rough estimate - are we talking days, weeks or months? I wont hold you to it!

 

Thanks!

 

Thanks that worked perfectly. Definitely faster than waiting for the fix

 

This half worked for me. It got rid of all the ref issues but i still cannot make a prefab of my camera without getting the errors in the screenshot attached (AssetImporter is referencing an asset from the previous import. This should not happen.) This was the same issue i had before.
I deleted it, and added again which has made the errors disappear. Not sure if i will still have an issue or not though.

 

I am was playing around and now i get this: "Disconnecting is no longer implemented"

 

Case: 1081152.
Finding this hard to explain but tldr; It was taking ages to strip the project without causing other issues that masked the actual error so apologies for the size. The Hierarchy is simple though with just the one object.