ERROR 87: Singular field on the edge of a triangle

Hello I'm making patch antenna , actually 2 patch antenna in a same plane in order to get interference from one to on another , antenna size is in mm .
But I'm getting this error 87 again and again
"The following message from the master process (MYID= 0):
Calculation of submatrices A3x ( 0% of the full matrix)
WARNING: Triangle 664
WARNING: Position X= -1.60745531E-007 Y= 2.17354439E-007 Z= 0.
WARNING: X= 0. Y= 1.E-006 Z= 0.
WARNING: X= 5.9716118E-007 Y= 5.5415199E-007 Z= 0.
ERROR 87: Singular field on the edge of a triangle"
Any solutions