Issues with meshing on GID and executing with LIGGGHTS

Greetings,

I've been having the same error for some time when meshing with GID and then executing a LIGGGHT's program.
After displaying information about elements that have 6 neighs, instead of the expected 5 neighs, it shows this:

ERROR on proc 0: Fix mesh: Bad mesh, cannot continue. Possibly corrupt elements with too many neighbors.
If you know what you're doing, you can try to change the definition of SurfaceMeshBase in tri_mesh.h and recompile (../surface_mesh_I.h:504)

I've executed a simulation without troubles already, what knocks me is the fact that, even using the same methods, others simulations using different cads doesn't seem to work. Note that, in the first simulation, besides running well, it still shows an error on some elements having 6 neighs, but still runs the program.

Any suggestion will be much appreciated,
Best regards