You may get this error message in Visual Studio Code terminal after installing Vue CLI.
Solution
Step 1: Navigate to the file location
Navigate to the file location mentioned in the error message. In my case it was:
C:\Users\ravi\AppData\Roaming\npm\
Step 2: Rename File
Now rename vue.ps1 file to anything like vue.ps1_renamed.
Done!!
This should solve the problem.