TOAD :ORA-12170 when trying to connect using TOA

The following error appeared when you are trying to conenct to database using toad applicaion: –



Make sure of the following :-

  • Database is up and running
  • Listener is up and database is registered using.

lsnrctl status

if the above steps is done and still facing the same issue then do the following :-

  • Right Click on my computer and choose properties.
  • Advance system settings.
  • Environment Variable.

check the below entry is exsits, if not add it by press on new and follow the same steps by adding TNS_ADMIN and the location of the tnsnames.ora, sqlnet.ora into the 2nd box like the picture below.