SURFACE DEFINITION ASSEMBLY__PICKEDSURF not found

[aeroengineer617]

Does anyone know what this error is?

SURFACE DEFINITION ASSEMBLY__PICKEDSURF234 NOT FOUND.
SURFACE DEFINITION ASSEMBLY__PICKEDSURF237 NOT FOUND.
THE SURFACE ASSEMBLY__PICKEDSURF234 HAS NOT BEEN LOCATED
THE SURFACE ASSEMBLY__PICKEDSURF237 HAS NOT BEEN LOCATED

I can see that the last 2 propagates from the first 2 errors, but exactly what is the surface definition assembly?

I've had this error in the past and usually solved it by remaking the model. That is out of question on this particular job.

 

[corus]

What you've done is to edit the model after you've defined the loads/contact surfaces and so the surface definitions have changed, or completely disappeared. When you do this you have to go back to each module and check all your loads are in the same place you originally defined them for.