Can't save track design...

[Raqxyz]

I just built a LIM launched coaster with what I thought was a fairly simple format/design.
It uses the default LIM Launched Roller Coaster Trains, and I was able to test it successfully. 
But, when I try to save it, I get the error message:
Can't save track design...
Track elements not supported by design format.

 

[jensj12]

That's because the track design contains elements that are not et supported by the track design save format, in particular the large corkscrew pieces (those were added by OpenRCT2 and not available in vanilla RCT2). Either save the park, or remove the large corkscrew pieces from the ride to save it.