today i downloaded 2 coaster designs, 2 water parks and 2 full sandbox game saves.

I pasted the .dat files into what i presumed was the correct folder for the coaster, hard not to miss as its named "rollercoasters", placed the sandbox game saves in, but when i opened up rct3 to play, it kept crashing, so i deleted the downloaded designs, lo and behold rct3 works again'

So, i dont know where to put them without the game crashing upon startup! especially dont know what to do with a full waterpark save

any help on this one?

Are you using a mac? If so I have the same problem and have just stopped downloading parks, it sucks.