Current solution contains incorrect configuration mappings

I get this error in VS:

Current solution contains incorrect configuration mappings. It may cause projects to not work correctly. Open the Configuration Manager to fix them.

I then open Configuration Manager, and click on Close and the error goes away.

I can then see it made these changes to my .sln file:

Why were the original configuration mappings incorrect?

It's not uncommon that shared projects get included in the list of projects to build. Not sure it applies to all cases but clearing everything between:

GlobalSection(ProjectConfigurationPlatforms) = postSolution

and

EndGlobalSection

in the .sln file and then reloading the solution will at least solve those.

It's not uncommon that shared projects get included in the list of projects to build. Not sure it applies to all cases but clearing everything between:

GlobalSection(ProjectConfigurationPlatforms) = postSolution

and

EndGlobalSection

in the .sln file and then reloading the solution will at least solve those.

In my case, it was because the .csproj file had the wrong profiles compared to the global profiles.

Ensure that the tag has the correct value. You'll probably find in said project something like:

<Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>

It should look like

<Configuration Condition=" '$(Configuration)' == '' ">Debug_VSTS</Configuration>

In my case, it was because the .csproj file had the wrong profiles compared to the global profiles.

Ensure that the tag has the correct value. You'll probably find in said project something like:

<Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>

It should look like

<Configuration Condition=" '$(Configuration)' == '' ">Debug_VSTS</Configuration>