since I installed sql developer and try to take the free course offered by oracle intro I can't connect to the server (in the case is pdborcl) and the ORA-12514 error appeared, after a few tries looking at forums and changing the tnsnames and listener files the ORA-12518 error now appeared.
what made it change to error 0ra-12518 was an attempt to change the files: listener and tnsnames.
I've been trying to solve for a week to learn about the platform
