The offering altar (Dobby's Altar in Dalby Forest, Eurvicscire as mentioned in the title) requires "5 Fabric" in order to complete it but if you have upgraded your Quiver and Rations to maximum by the time you get there you do not get fabric as loot anymore and in my case had no more in my inventory since I upgraded the first chance I got. I know the resource is gone because I'm now level Power 312 and loot everything in sight across multiple regions in an attempt to 100% each zone and fabric has dried up completely even in level 200-300 areas. This leaves me in a position to where it is now impossible to complete the region without either a patch or in the distant future some upgrade to the Quiver or Rations makes fabric an obtainable resource again. I'm not sure if this is a bug/glitch or gameplay issue, but you may want to look into it because you have a lot of region completionists out there like myself that will likely become quite annoyed by an inability to complete all regional mysteries.