Licensing for Server Express Remote Development Option (RDO) is managed by the remote server and this includes issuing the Windows client license. When you start the Eclipse IDE for the first time on your client machine you will be prompted to enter the details of the license server. 

If you make a mistake in entering the license server details, communication between the client machine and the license server machine will fail, thus returning the error message:

ServerExpressRDO: Error: Feature "ServerExpressRDO" is not licensed to run on this server

When you start up the Eclipse IDE on the client machine, it only prompts for the license host the first time.  In so doing it creates a file called licensehost.txt which is stored somewhere on the client machine.  Having incorrectly entered the license server details, you will need to locate this file and then delete it.  In so doing, the next time the Eclipse IDE is started up, you will be prompted to re-enter the license server details.