"Aborted Retargeting for the following pose group(s). Retargeting without AutoSolve requires at least 2 poses."
Attempting to open a performance with a character setup file that only contains one expression will abort the AutoSolve. You need at least two active (checked on) related to the group (Eyes, Mouth, Brows) that you are attempting to AutoSolve.
If you intend to use AutoSolve, then make sure that you have at least two expressions active for a given group when you create the Expression Set within your character setup file.