M-Files COM Error: Network problems are preventing M-Files from communicating with the server. The RPC Server is unavailable

In addition to what Craig said when it comes to the gRPC protocol:
1. the default communication port is 7766, not 443. This may be the case if it is through a reverse proxy or in the cloud
2. There must be a valid SSL certificate installed on the server (and on the proxy if such is the architecture), which the client can trust.
If these conditions are not met, it is normal to return the above error

In addition to what Craig said when it comes to the gRPC protocol:
1. the default communication port is 7766, not 443. This may be the case if it is through a reverse proxy or in the cloud
2. There must be a valid SSL certificate installed on the server (and on the proxy if such is the architecture), which the client can trust.
If these conditions are not met, it is normal to return the above error

Hello Ne0Tr0n.  This is a cloud vault so I assumed the SSL cert was handled by M-Files?

If this is a cloud vault then we can get rid of most of the technical considerations, as well as firewalls and things, as they are managed online.

I just checked here and I believe the protocol sequence should be the string "grpc" and endpoint the string "443":

var serverApplication = new MFilesAPI.MFilesServerApplication();
var connectionData = new ConnectionData()
{
	NetworkAddress = "myvault.cloudvault.m-files.com",
	ProtocolSequence = "grpc",
	Endpoint = "443"
};
serverApplication.ConnectAdministrativeEx5(connectionData, MFAuthType.MFAuthTypeSpecificMFilesUser, "MyUsername", "MyPassword");

Thanks Craig and Ne0Tr0n, I added the following cast and it worked before I tried the method you recommended

I appreciate the help!