Two of my friends have broken rj45 sockets in their kemper racks. They still work, but they don't hold the cable tight(yes, cable and nose is ok, its the socket). This can happen when someone accidentialy pulls hard on the cable while plugged in.
It is possible to change them. But you have to disassamble the whole unit to get to this point, and have to solder the small connectors.
If you don't live in the US getting the spare part costs about 35€ or more, cause you only find shops in the US that sell them.
I am glad I put my patch panel in then ;). While I live in the US and am a seasoned electrical engineer, cracking open my KPA and soldering on the weekend is not my idea of a great time either.
You should be able to find the parts in Europe easily enough. Perhaps if you check Digikey you could find a distributor in the EU that has them.