ORA-06550: This error is raised when there is a syntax error in the PL/SQL code that is being executed. Check for any typos or missing parentheses in your function call.

ORA-06503: This error is raised when the function being called does not exist or is invalid. Make sure that the function name is spelled correctly and that it is defined in the appropriate schema.

ORA-06502: This error is raised when there is a data type mismatch between the input parameters and the function definition. Check that the data types of the input parameters match the data types expected by the function.

ORA-06512: This error is raised when an exception is raised within the function being called. Check for any error handling code within the function that may be causing the exception to be raised.

ORA-04068: This error is raised when the function being called is invalid or in an invalid state. Recompile the function using the “ALTER FUNCTION” statement to resolve this issue.