Error #1000, found blank

Hey,

I'm trying to set up a model with Optistruct which got an area connector to simulate the glue but i get the following error:

178593:PSHEAR, 6, 4
 
 *** ERROR # 1000 *** in the input data:
 Incorrect data in field # 4.
  Expected REAL > 0, found  BLANK.
 
I tried to fill in some values but then it will become error 14, and i can't find what im doing wrong.

Can you please help me with this?

Thanks in forward.