Recently when working with Oracle Data Pump I got strange error, that got like 2 results on Google, non of them solving the issue. So I thought I would share a solution.
expdp: symbol lookup error: expdp: undefined symbol: lmxconpar2
The reason was improperly set path in /etc/ld.so.conf file. The PATH was pointing to Oracle Instant Client version 12.2, while ld.so.conf was pointing to libraries for version 12.1. Setting them both to version 12.2 and running sudo ldconfig solved the issue.