Problem with mirror

Hi everyone,
when I use the function "mirror" in a shelled part Alibre doesn't do it. Appear this error message if I try to do it after:

RBI_NO_LUMP_LEFT: no lumps left in body

What do you mean?
Con someone help me?

Thanks a lot,
Francesco

 

Francisco,
Place the Shell after the MIrror. For some reason Shell cannot be mirrored since is acts on the whole part.

 

Thank you so much Harold.

Francesco