ORA-01008: not all variables bound. They are bound

Question

I have come across an Oracle problem for which I have so far been unable to find the cause. The query below works in Oracle SQL developer, but when running in .NET it throws

Answer 1

Came here looking for help as got same error running a statement listed below while going through a Udemy course:

INSERT INTO departments (department_id, department_name)
                  values( &dpet_id, '&dname');  

I'd been able to run statements with substitution variables before. Comment by Charles Burns about possibility of server reaching some threshold while recreating the variables prompted me to log out and restart the SQL Developer. The statement ran fine after logging back in.

Thought I'd share for anyone else venturing here with a limited scope issue as mine.