I can spawn everything fine, except on C6_m1 (The first map of the passing, haven't tested it on any of the other 2 passing maps) if you attempt to spawn a witch, the server will then crash.
EDIT-
Just tested the other 2 Passing Maps. I can spawn Witches just fine on Passing maps C6_M2 - C6_M3. Its C6_M1 (The first Passing Map) that will crash the server if you force a witch to spawn. Probably has something to do with the bridge witch perhaps?
Could you try spawning a witch witch this plugin and see if server still crashes?