Lines that go from 2d to 3d

[elim_aguilare]

I work with Civil 3D drawing in 2D with lines, but out of nowhere, some of them turn into 3D. I tried to find a solution, but I’m not an expert in this and need help. Sorry for any spelling mistakes; English is not my native language.

[AllenJessup]

Are these Featurelines of plain AutoCAD lines?

[elim_aguilare]

Yes, simple lines. The strange thing is that if I work on the drawing on another PC, it works normally.

[AllenJessup · Accepted solution]

So if you draw using the Line command the elevation of one end of the line is different that the other end of the line? Is one end at 0?

Are you using OSnaps? Check your Elevation variable, type Elevation at the command line. Do you have any Xrefs attached? Are you working in a UCS?

Sorry for all the questions. But, it's difficult to pin down the problem without more information.

[elim_aguilare]

If you're right, it's very hard to know that way. Answering the first question, some lines simply go below the drawing but all of them have the same Elevation. For the second question, yes, I use Osnaps. And for the third one, no, I don't work in UCS.

I'm going to check the Elevation variable. Thank you very much for your help.