Did you recently use the TD with your PC hooked up to a secondary display? If you did, and you have the display preferences (within the TD) set to remember dialog locations, then the dialogs are likely opening off-screen (where your extended display was previously located).
There's an undocumented hotkey that will recenter an open dialog on the main display. Press the R key while holding down Ctrl and Alt and Shift. You can do this at any time to recenter the currently open dialog. Once you start the TD, press this hotkey. Hopefully a dialog will "pop" into the middle of the screen. If it's not the Settings window, close the dialog and press the hotkey again. Repeat until you get to the Settings window. Then go to the Preferences tab, select "Display Management", then choose "Open all dialogs: centered on the Main display" in the "Dialogs" section located on the right side.
There will be another hotkey in the next version that will recenter ALL open dialogs and set this preference for you, added just for situations like this.
Well, I hope this is what's going on with your TD.