To access Uurathor's hut in Raal Grotto without using magic, you have to pull a rope which raises a platform. The problem is that the outside rope, TR_m4_act_pull_rope, is trying to move a non-existing platform called TR_m4_act_rats_platform, whereras the only movable platform in the cell is called TR_m4_act_rats_platform2. I suspect this may be a remnant from a previous iteration of the interior with two platforms (since both platforms are available in the object window), but since this is no longer the case, the script needs to be modified to point to the right object. An alternative could be to use the same script for both ropes, but since there seems to be a slight difference in functionality, modifying TR_m4_act_pull_rope_script might be a better option.