While the DLL search path fixer should keep this from happening, Managed-OSVR shouldn't silently fail if it can't load the DLLs it's trying to p/invoke, which is most difficult when it's a dependency of the invoked DLL that's missing.
On a related note, if the directly-invoked DLLs are missing (such as when trying to run a 64-bit Unity build when there's no 64-bit Unity plugin yet), that should also be a visible error condition.
While the DLL search path fixer should keep this from happening, Managed-OSVR shouldn't silently fail if it can't load the DLLs it's trying to p/invoke, which is most difficult when it's a dependency of the invoked DLL that's missing.
On a related note, if the directly-invoked DLLs are missing (such as when trying to run a 64-bit Unity build when there's no 64-bit Unity plugin yet), that should also be a visible error condition.