There is a beam to beam connectivity issues in your model. You can identify beams which are not connected to the other beams correctly by going to Tools -> Check Multiple Structures. This issue can be fixed by selecting all members and using Intersect command in the Geometry -> Intersect Selected Members menu.
There is also 1 node which is not connected to the structure and it can be removed by going to Tools -> Orphan Nodes -> Remove.
There is also 1 node which is not connected to the structure and it can be removed by going to Tools -> Orphan Nodes -> Remove.