CT Poseidon and The Smiler CT

I see that both have a good number of downloads but it seems myself and one other is having a problem with both crashing the game. I've post on the download page but no answer to why either game is crashing.  Can anyone help?  Both look really good and I'd like to have them in the game but I think I may be missing some CT that is needed.  Please check my comments and see if you have an answer.  Thanks.

If you have these installed correctly, they both work. But you need to have shadows turned OFF. Placing objects from the themed folder will cause the game to crash if you have shadows ON. And building the Smiler CT will also cause the game to crash when placing the 4th section of track. So I'm pretty sure that's your problem.

Also, some CT's have been known to cause crashes for some people and not others.