Error when executing python code in SQL server

I have installed machine learning services R and python In-Database features to my SQL server, also I have enabled sp_execute_external_script and restarted the server as mentioned in the documentation, but when trying to run some python code I receive the following error:

Msg 39021, Level 16, State 1, Line 0
Unable to launch runtime for 'Python' script. Please check the 
configuration of the 'Python' runtime.
Msg 39019, Level 16, State 2, Line 0
An external script error occurred: 
Unable to launch the runtime. ErrorCode 0x80070490: 1168(Element not 
found.).

Could anyone please help how to fix?