There are no code coverage indicators in Visual Studio text editor even though the coverage is not zero

Problem

There are ReSharper and dotCover installed, tests were run using Cover, but no code coverage is shown in the gutter. Although the coverage is not 0%.

Resolution

Check if the Highlight code is enabled on the toolbar of the Coverage Results Browser or Unit Test Coverage.

Or choose (Extensions) | ReSharper | Cover | Toggle Code Highlighting from the main menu or on the icon in the scrollbar.

More information can be found here: Visualize code coverage in the editor.