Without going into system programming group ring cannot be disabled, if just out of blue stop working I would say corrupt data and system re-boot should be tried. This comes with a warning, the system is old and the CPU battery could be bad, power cycling to re-boot the system could default the data base. Back up the data base if you can, this will take the DSX software and there are 2 different versions, 1 for DSX software up to 2. and the other for systems with software versions beginning with 3.

We get old too soon, smart too late