This is somewhat easy solution.    Check to see if your  target database has the user you are trying to import.  If not, you may want to create the user first and then import.   Or you can simply do FROMUSER TOUSER to another user.

Another solution would be to take full export with rows=n and try to get all the schemas imported with full=y and rows=nn this way you got the schemas going.  Then do an import with rows=y .    

Hope this helps,

Thanks,