: Many solutions online focus on library paths, but the actual root cause is often NLS (National Language Support) - SQL*Plus can't find its language-specific message file, usually sp1<lang>.msb in $ORACLE_HOME/sqlplus/mesg/ .

This is a classic on Unix/Linux. Error 57 usually points to a missing or incompatible system library or incorrect environment variables .

What OS and Oracle version are you running? That would help narrow down the exact fix.