While running a code of Patch Antenna, I am getting an error:
Segmentation error, that is two triangles are touching each other but have no common vertex. How do I remove this error.
This error could happen when you have two plates (or sth else) in fact share a common egde, but when you perform meshing, FEKO treats the two objects separately and the triangles don't share nodes at the interface.
You may try to do the "union" in CADFEKO for the parts to make sure they really share the common edge in the mesh, if you have FEKO version 5.0 or later. But since you are talking about WinFEKO, apparently you are using earlier version. In this case, you may try to add "maximum identical distance" of 1e-5 or sth similar to the EG card. This may cure the problem.
For your information, you can also request an evaluation version of FEKO 5.1.1 which is fully functional for 45 days at the link below http://www.feko.info/feko/evaluate