Not enough information. Please send your file to techsupport@coade.com and I will have a look. Note that a single +Y support on an otherwise unsupported pipe is statically indeterminate, which could be the problem.
_________________________
Loren Brown
Director of Technical Support
CADWorx & Analysis Solutions
Intergraph Process, Power, & Marine
12777 Jones Road, Ste. 480, Houston, TX 77070 USA