Sometimes telescope driver stop operating. Most probably it is some weird error of Gemini. You will see in rts2 on T0, that it is moving, but DEC will not change (usually only DEC does not change).
To solve it:
su killall rts2-executor killall rts2-teld-gemini /etc/init.d/rts2 start rts2-mon
Then issue park command on T0. See if it parked (changed state from PARKING to PARKED). After that, run executor.