Squeezebox receiver and controller problems

Lately my Squeezebox Duet system has stopped working. It has worked perfectly the last month, but some days ago it suddenly decided not to. Until now I've not been able to solve the problem.

The receiver is connected by ethernet and the Squeezebox server is running on a Synology NAS.

Here is a list showing the things that I've tried:
- Done a factory on both devices(Receiver and Controller)
- Turned off the DHCP server in the router(though I wasn't 100% sure what I was doing)
- Made a DHCP reservation in the router for the Squeezebox server.

Do you guys have any idea what the problem is and how I fix it?

Regards
Jonas