Commit
569a02a2d2575eb52d740d33cacdb5ddba274105
by agoodwinworkaround Paper CraftSign bug
Paper deleted a null check that Spigot has, so just do the null check in Denizen code - see for reference https://github.com/PaperMC/Paper/blob/06db5d08b08c4f53fea9cb322127b3a3311bbcd9/patches/server/0011-Adventure.patch#L2029-L2044
(commit: 569a02a)