One of the databases I have recently upgraded to Oracle 12cR2 , the export datapump was failing and never continues to finish. This was wired….the following errors were thrown in the export log file:

ORA-39374: Statistics failed to export. Failing error is
ORA-01732: data manipulation operation not legal on this view

To troubleshoot this problem:

Try taking full database export datapump with the clause “EXCLUDE=STATISTICS“

if this doesn’t fix your problem then check the parameter size of streams_pool_size it should be at least 300 MB. changing this parameter value actually fixed my problem !