Forums across the internet suggests several options to resolve this issue (like changing the active window title height to 18+ , removing the “Toad for Oracle” folder from AppData, etc.); however all of them are futile and will not work (at least it didn’t for me). The simple solution is to use the Session -> Connect menu option, and if you do that, TOAD will not throw this weird error message. I remember reading somewhere that this is a known bug and addressed in TOAD ver 12.0 onwards.
You must have noticed that the connections that were opened in the past are listed under the Session -> Connect menu. Actually TOAD stores these settings in the “C:\Users[USER_NAME]\AppData\Roaming\Quest Software\Toad for Oracle\11.0\User Files” folder. If you browse this folder you will find three key files:
The Connections listed in the Session -> Connect menu is retrieved from the CONNECTIOINS.INI file, and in case you have choose to save the password; the encrypted password is stored in the CONNECTIONPWDS.INI. In case, you don’t have a connection saved in the list, you can make an entry in the CONNECTIOINS.INI and in the CONNECTIONACTIONS.INI file using the same structure used for all other saved connection entries. Don’t bother to put the password in the CONNECTIONPWDS.INI; as in case TOAD won’t find one, it will prompt you to enter. Remember, while making an entry in the CONNECTIOINS.INI, make sure to choose the “LOGIN” and “RelativePosition” position values such that it’s not assigned to any other saved connection. Also note that, you must have the “Server” entry available in your tnsnames.ora, in case you wish to connect the DB using TNS protocol. Just by having this entry will not allow the new connection to be reflected in the “Session -> Connect” menu, in case it has already crossed the maximum number of “quick connect” options. You need to alter the Toolbars/Menu options by opening “Toad Options” from View menu. For instance, change it to a larger value so that all connections available in the CONNECTIONS.INI are listed there.
Hope this helps.