Erik Kostson
Ansys Employee
PLease see the video, and search the terms shared topology or multi-body part. These do not merge parts into one, but they share common features between parts (say a common face or vertex,..).

This is the solution to the issue/error so learn how to use share topology.
(So the error is due to the fact that the two beams/parts are not connected at their common vertex)

Closing this one as this resolves it.
Good luck