ORA-06520
PL/SQL: Error loading external library
Cause
An error was detected by PL/SQL trying to load the external library dynamically.
Action
Ensure that the dynamic library exists, that it is installed correctly and that it is not corrupt or otherwise unreadable by the operating system. Also, ensure that the library path in the LIBRARY object is correct, including the values of any environment variables used in the library path and the directory path values of any DIRECTORY objects used by the LIBRARY object.