# 'Unable to import' error message in Q# using VS Code

I'm a complete beginner in Q#.

Consider the code in the following image:

For some reason, there always is an error message when I try to import anything. It also implies to keywords like Length. The error message is :

No namespace with the name "Microsoft.Quantum.Canon" exists.


However, my code works just fine. The code in the image is taken directly from user guide of Q#.

Any Suggestions?