ERROR: Element quality check

Hi all,

 

I have a problem regarding the Optistruct Element quality.

 

 Element # 6837, element type QUAD4.

 ERROR - Validity limit violation: Vertex Angle =    297.45   

         upper limit =    180.00

 

i run a bead optimization and although I use the card 

 

PARAM,CHECKEL,NO

 

it seems to make the element quality check and show the ERROR. 

 

 

Can you help me what is wrong with my mesh. To me it seemes to be a regular mesh.

 

Thanks,

 

Uroš

<?xml version="1.0" encoding="UTF-8"?>