You can't complete the last part of the Eliminating the King Sage Cat quest because you can't enter Hidden Street: Forest of the Ghost Priest. As http://bbb.hidden-street.net/quest/mu-lung-nihal-desert/eliminating-king-sage-cat lists, as you enter the map, you get a notification from the Maple Administrator to go into the Forest of Ghost Priest. But, as you cannot enter that hidden street, the quest ends prematurely. http://maplearchive.com/quest-wp.php?id=3844
Handsome encountered this problem, too; I did some research and found out the map in question (Forest of the Ghost Priest) doesn't exist in MapleRoyals: It's just not in the files. Probably easy to fix, then, since you merely have to add the map and according NPC.
I think the hs at Stairway to the Sky (Eliza's garden) needed on the Goddess's Pet quest isn't working either. I tried to contact a gm to check it out, but no one answered me, so I can't say that for sure.
Did you test it also on a non-GM character, Marty? I've noticed that sometimes GM characters can gain access via regular means (ie not warping) when players can't - for example, getting into Spiegelmann's Office (CPQ) at level 51+
