Solution "D:\a\HashTableRx\HashTableRx\src\HashTableRx.sln" has active build configurations for the build project.
Either enable SuppressBuildProjectCheck on "Build.Solution" or remove the following entries from the solution file:
" - {5A3634B0-A15E-4B5D-8367-7D9FD0EACEE2}.PreRelease|Any CPU.Build.0 = Release|Any CPU"