Library\PackageCache\com.unity.package-manager-ui@1.9.11\Editor\AssemblyInfo.cs could not be found | Solution

You may get dozen of errors like

Library\PackageCache\com.unity.package-manager-ui@1.9.11\Editor\AssemblyInfo.cs could not be found. 

1.       You may get the UI package Manager error after importing UI package. Now for the solution to the UI Package Manager problem. Follow the below steps or watch my below video guide:

1.     Go to Window -> Package Manager
2.    Click on package Manager UI
3.    Click to Update the Package

The error will disappear, see the below video:

Library\PackageCache\com.unity.package-manager-ui@1.9.11\Editor\AssemblyInfo.cs Solution