I got the following error message when using impdp :

ORA-30036: unable to extend segment by 4 in undo tablespace 'UNDOTBS01'
ORA-39171: Job is experiencing a resumable wait.
ORA-30036: unable to extend segment by 4 in undo tablespace 'UNDOTBS01'
ORA-39171: Job is experiencing a resumable wait.
ORA-30036: unable to extend segment by 4 in undo tablespace 'UNDOTBS01'
ORA-39171: Job is experiencing a resumable wait.
ORA-30036: unable to extend segment by 4 in undo tablespace 'UNDOTBS01'
ORA-39171: Job is experiencing a resumable wait.
ORA-30036: unable to extend segment by 4 in undo tablespace 'UNDOTBS01'
ORA-39171: Job is experiencing a resumable wait.
ORA-30036: unable to extend segment by 4 in undo tablespace 'UNDOTBS01'
ORA-39171: Job is experiencing a resumable wait.
ORA-30036: unable to extend segment by 4 in undo tablespace 'UNDOTBS01'
ORA-39014: One or more workers have prematurely exited.
ORA-39029: worker 2 with process name "DW02" prematurely terminated
ORA-31672: Worker process DW02 died unexpectedly.
Job "SYS"."SYS_IMPORT_SCHEMA_03" stopped due to fatal error at 16:30:38
ORA-39014: One or more workers have prematurely exited.

This was pretty clear cut.   My undo tablespace needed tuning.

I updated my undo_retention and set it to 900 :

alter system set undo_retention=900 scope=both;

I added another undo datafile and then kicked off the import again and it went through fine.