ORA-20250: A user specified error message

Error messages starting from -20000 until -20999 are user specified error messages.

Oracle provides these range of codes so applications can raise an application specific error, which will be displayed after the chosen code.
This is done using the raise_application_error pl/sql function.

You'll have to contact the application provider should you want to have more detail about the error message.
Unless the error message is of an Oracle application or functionality, it is useless to contact Oracle for these errors.

Imagine I have a procedure which takes an argument. This arguments needs to be between 0 and 100:

create or replace procedure add_salary(pRaise number) is
begin
  if pRaise not between 0 and 100 then
    raise_application_error(-20000, 'Raise need to be between 0 and 100');
  end if;
  -- do further processing
end;
/
Procedure created.

SQL>

Now we test the procedure with a valid argument:

SQL> exec add_salary(0);

PL/SQL procedure successfully completed.

And now with an invalid argument:

SQL> exec add_salary(110);
BEGIN add_salary(110); END;

*
ERROR at line 1:
ORA-20000: Raise need to be between 0 and 100
ORA-06512: at "DEV01.ADD_SALARY", line 4
ORA-06512: at line 1

As one can see, we raised a custom error -20000 with a user defined error message.
The same thing happened with you, if you receive this error with one of our applications, you need to contact us in order to solve this problem.

So the only one who can help is the application vendor or service provider.