A review of the logs will yield an error similar to this:
2018-01-01 01:11:11,602 WARN [STDERR] (RPC-thread-1 - name.servername.com:2595:2167964350049439103:) com.teneo.esa.export.pst.PSTProcessException: [#116005] Export Error - wrapped exception - [#80000] Common Services Error : cannot create directory - \\export\cw\collections\0.6.962.1909515269\1.5.962.8201305627272675351\doe_ john\BPOS:
This is caused by the : (colon) being inserted into the path. Colons are considered an invalid character.
Select Single File instead of Multiple File for the export when running the next export.