[Package Manager Window] Cannot perform upm operation: Unable to add package [com.unity.animation.rigging@1.0.3]:
One or more dependencies could not be added to the local file system:
com.unity.burst: EBUSY: resource busy or locked, open ‘E:\my project\Prototype1\Library\PackageCache.tmp14532lFfhjh5mJ7vF\copy\Runtime\Intrinsics\x86\Sse2.cs’
com.unity.mathematics: EBUSY: resource busy or locked, open ‘E:\my project\Prototype1\Library\PackageCache.tmp14532b2IwjDVJlD6S\copy\Unity.Mathematics\math.cs’
Unable to add animation rigging package gives error,i am unable to install animation rigging package
Maybe too late to help, but try closing your IDE (Visual Studio Code, etc). This sometimes locks a bunch of files, for some reason, and prevents install.