Unable to connect. Getting the error:
"The program can't start because oracore12.dll is missing from your computer."
Go to Toad's login screen and under 'Connect Using:' drop-down box, use or try the other clients in there, if any.
Note: if you have an active connection, the 'Connect Using:' drop-down box will be disabled or grayed-out. Disconnect all connections first for this box to be enabled.
If you do not have any other Oracle Clients installed in your PC, re-install your Oracle Client.