***Operating on an imported orphan mesh***

Dear group members,
I imported into Abaqus an input file(only model data) generated by 
third-party preprocessor. This procedure is successful. Next, I 
defined some surfaces(solid-element-face based) in Assembly module. 
Then in interaction module, I need to define shell-to-solid coupling 
constraint on my model. The problem is that when I try to select the 
solid surface defined previously, this selection is always 
unsuccessful. The error msg is like:"a solid surface must be 
selected to accomplish this constraint"(may not be exact, but the 
meaning is the same). Why this happen? Why the surface I defined on 
solid elements can not be used or selected?
I also wanna know on earth what operations we can perform on an 
imported mesh and what operations will corrupt the original 
definitions( like node sets, element sets, etc) in the original 
model data. 
Can anyone help me? Thanks a lot.








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