Sometimes we hit a key or perform an operation by accident and find that our Screenbuilder main screen or even the layout canvas or preview window just disappears. If you have another screen, maybe that's where it went. If you don't have another screen, that's still probably where it went, but now you have a problem.
To resolve this issue, you can hack a registry key to reset the window positions. If you've never hacked a registry key before, proceed at your own risk. If you follow these instructions you will be fine, but one wrong move can mess your system up pretty badly.
Open the registry editor. You can type "Registry Editor" into the Windows search field on the taskbar or type the command
regedt32.exe
at a command prompt. This will open a window into the Windows registry, where many programs store certain types of data.
Navigate to the registry key you see outlined in red above. Look to the right-hand side of the screen for the posX and posY values, outlined in green in the screenshot. These are the x-y coordinates on the screen, where the top left corner of the screen will be when you start the program.
Double-click on each value and change it to decimal zero:
Just click OK for each; there is nothing else to save. Now you can close the Registry Editor and re-open the program and you should see all the program's windows.
Note that below the entry for "builder" there are additional entries for each script you have. You can follow the same procedure to change the locations of windows for each of your scripts if needed.