Line load


I am struggling with a weird error and I cannot understand why it is happening. I have done some polylines in a dwg file and then used 3DM to convert it inside grasshopper. The final geometry will consist of some different elements as shown in the picture below:

Then I am using structural line to export the geometry to sofistik, where I want to apply a line load with teddy as it follows, but I get an error for only 2 of the 3 lines (line 1000 and 1001). They seem to have the same elements inside so I cannot wrap my mind around the issue

Has someone already experienced this?