I have installed RMS on a number of servers. At least 40% cannot install. All have the same issue and when checking the Deployment List the server in the portal, all have a license key of bnVsbA==.
So it appears an error when the key is generated as instead of going to the Install Module screen after Apache is restarting (after buying the license), it goes back to the RMS module screen.
Exact same error on many of the servers with the same Trial license key.