Nearly all user created "working" benches, tables, and guest hacks were created before CC. So these will be incompatible with CC. Having any will cause guests to stick to Zoo Tycoon's benches, tables, grandstands, and outdoor attractions. Just having them in a Zoo Tycoon folder will cause the problem, even if none are actually used within a zoo. You should move any user created "working" benches, tables, and guest hacks that you have so they are no longer in any Zoo Tycoon folder.