Sorry, mistyped the number. It is 4.0.9.2504, same as shows up for you. Sounds like system lost track of the current version.
What I try is this:
Go to
https://forum.runesofmagic.com/showthread.php?t=363202
Download latest patch - patch_4.0.8.2506.en_4.0.9.2504.en.exe
Once downloaded, run it. That should, in theory, update the relevant files to whatever system is checking. After update they should be all consistent, and the client should let you go into the game.