"Missing or unspecified Language attribute" when importing snippets

Question

When importing a directory containing snippets in the Code Snippet Manager in VS2017 (v15.7.5), in the Output pane I get the warning

Missing or unspecified Language attribute

even though a language attribute is present. I even get this when importing Microsofts own snippets. The snippets are for C#.

How to import the snippets?

Answer 1

At the top of the Code Snippet Manager there is a dropdown where you have to select the language for which you're importing snippets; if a different language is selected you could get this warning.