Cause
An attempt was made to use the Multilingual Engine (MLE) with Multi Process Multi Threads (MPMT) enabled.
Action
Disable the Multi Process Multi Threads (MPMT) before using the Multilingual Engine (MLE). Retry after MPMT is disabled.
Oracle 26ai
ORA-04254
Error Message
Multilingual Engine (MLE) does not support Multi Process Multi Threads (MPMT).