CRM 2011 Import solution hangs on on progress bar
On checking found that one organization was on roll up 17 but rest were on roll up 12.
This org was imported via a databse from a different user and that user had up to date roll up where remaining/base were on roll up 12 on my system.
CRM was expecting all organizations to be on same roll up, at least base one.
By updating everything to roll up 17 fixed the issue