Symptom

1.  BarTender freezes when trying to open a dialog.
2.  BarTender itself might not seem to be starting.

Environment

 Usually, when user is working or has worked with more than one monitor.

Fix/Answer

1. Press Alt+Space
2. Press "m" key on the keyboard
3. Now use the arrow keys on the keyboard once or twice.
4. Move your mouse around.

This should result in you seeing a vague dotted outline of your dialog-box. Once you're able to see that hit enter to re-position it and later on resize it.

Alternative solution

Hold down the WINDOWS and SHIFT keys and then press the left or right arrow keys on the keyboard. This normally moves a window from one monitor to another and may pop the missing dialog box into view.