Bug How can I solve this error with Package Manager?

Hello, so these last 3 days I've been trying to resolve the following error, it happens whenever I open the Package Manager, in My Assets, also when trying to download an asset and when trying to import it:

 

IsReadOnly is not implemented by this handler UnityEditor.PackageManager.UI.Window:ShowPackageManagerWindow(UnityEditor.MenuCommand)



IsReadOnly is not implemented by this handler UnityEditor.EditorApplication:Internal_CallDelayFunctions()



IsReadOnly is not implemented by this handler UnityEditor.EditorApplication:Internal_FocusChanged (bool)



IsReadOnly is not implemented by this handler UnityEngine.GUIUtility:ProcessEvent(int,intptr,bool&)



IsReadOnly is not implemented by this handler UnityEditor.AsyncHTTPClient:Done (UnityEditor.AsyncHTTPClient/State,int)



IsReadOnly is not implemented by this handler UnityEditor.PackageManager.UI.Internal.AssetStoreDownloadManager/DownloadDelegateHandler:OnDownloadProgress (string,string,ulong,ulong,int)



Failed to import package with error: Couldn't decompress package UnityEngine.GUIUtility:ProcessEvent (int,intptr,bool&)

Versions where this error showed: 2021.3.8f1 & 2022.1.14f1

I've been looking everywhere and I haven't found a real fix for this, so I will try to list all the things I've tried:

• Restart Unity
  
  
• Restart Unity Hub
  
  
• Log-out and log-in
  
  
• Reinstalling Unity
  
  
• Installing new Unity Version
  
  
• Resetting packages to defaults
  
  
• Updating all modules
  
  
• Deleted the Asset Store-5.x folder
  
  
• I made sure I had enough space in my disk
  
  
• Renaming Unity Packages (making sure there is no wierd characters or spaces)
  
  
• Renaming Folders (making sure there is no wierd characters or spaces)
  
  
• Went to Project Settings > Player > Other Settings > Scripting Backend and changed it from Mono to IL2CPP

I'm kinda desperated already, but hopefully someone can help me solve this.

 

I am having the same issue now. I have done pretty much all of the same troubleshooting.

A lot of my assets won't import.

 

Extra unwanted packages in new projects (collab, testing, rider and other junk):

https://forum.unity.com/threads/temp-unityengine-testrunner-dll-error.1133938/#post-7287748

About the fastest way I have found to make a project and avoid all this noise is to create the project, then as soon as you see the files appear, FORCE-STOP (hard-kill) Unity (with the Activity Manager or Task Manager), then go hand-edit the Packages/manifest.json file as outlined in the above post, then reopen Unity.

Sometimes the package system gets borked from all this unnecessary churn and requires the package cache to be cleared:

https://stackoverflow.com/questions/53145919/unity3d-package-cache-errors/69779122

 

do you resolve the issue?

 

I resolved it.

clean/redirect/reset the cache folder for package manager

 

The solution provided by #5 works for me.
And I find another probable reason which may cause this issue: the names of your cache folder and asset folder may include invalid letters or punctuation mark. I used to store my assets under D://cache!/...., where the "!" may be the cause...

 

I am trying to extract Stronghold Definitive Edition graphic assets (see above). Keep getting the
'Failed to import package with error: Couldn't decompress package' error. How can I go about this?