This issue with PVS-Studio is caused by the mismatch of selected project's platform configurations declared in the solution file (Vault.sln) and platform configurations declared in the project file itself.
For example, the solution file may contain lines of this particular kind for concerned project:
{F56ECFEC-45F9-4485-8A1B-6269E0D27E49}.Release|x64.ActiveCfg = Release|x64
However, the project file itself may lack the declaration of Release|x64 configuration. Therefore trying to check this particular project, PVS-Studio is unable to locate the 'Release|x64' configuration. The following line is expected to be automatically generated by IDE in the solution file for such a case:
{F56ECFEC-45F9-4485-8A1B-6269E0D27E49}.Release|x64.ActiveCfg = Release|Win32
In automatically generated solution file the solution's active platform configuration (Release|x64.ActiveCfg) is set equal to one of project's existing configurations (I.e. in this particular case Release|Win32). Such a situation is expected and can be handled by PVS-Studio correctly.