I had a hard time with this too. Go to HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Lsa. Under a subkey you should see FipsAlgorithmPolicy. DELETE this registry entry and restart visual studio.
REF: https://blogs.iis.net/webtopics/parser-error-message-this-implementation-is-not-part-of-the-windows-platform-fips-validated-cryptographic-algorithms-when-net-page-has-debug-true