Hi there,
I have just downloaded 2019.3.5f1 and I wanted to add Entities package to a new project. This is what I have got as an error message in Console:
Cannot perform upm operation: EBUSY: resource busy or locked, open ‘-----\Library\PackageCache.tmp6760amsihKOTPeMr\copy\Unity.Entities\ConverterVersionAttribute.cs’ [NotFound]
UnityEditor.EditorApplication:Internal_CallUpdateFunctions()
Error adding package: com.unity.entities@0.6.0-preview.24.
UnityEditor.EditorApplication:Internal_CallUpdateFunctions()
Sorry to see that you are having this issue. Could you please include the editor logs. It could be some kind of permission issue on the folder. Maybe a super eager antivirus removing the files?
If you try in other Unity versions do you have this problem?
I had the same issue recently. Simply go to the folder location specified, open the folder properties window and make sure to have Read Only unchecked so that Unity could have read/write access to that directory. Hope this helps!
Same issue, happens a LOT. And theres usually no way to move forward, you can try removing your library folder etc reimporting everything. Been seeing this for ages now! Unity need to actually solve these type of issues asap, essentially they brick the whole damn package manager, and in extension the whole engine.
It seems to try to be smart behind the scenes to facilitate code completion, “go to definition,” and other features. It probably has to open a lot of files to maintain that sort of context.