Make sure you have the latest versions of both Adobe Air and svBuilder-Pro installed.
Adobe Air can be downloaded from this page: http://get.adobe.com/air/
The latest version of svBuilder-Pro can be found inside the SimpleViewer Pro zip package which can be downloaded using the link in your purchase email.
If uninstalling and reinstalling both programs does not help, then try the following:
1) Close svBuilder-Pro
2) Delete this folder:
Mac: /Users/your_username/Library/Application Support/Adobe/AIR/svBuilder-Pro
PC (XP): C:\Documents and Settings\your_username\Application Data\Adobe\AIR\ELS\svBuilder-Pro
PC (Vista, Win 7): C:\Users\your_username\AppData\Roaming\Adobe\AIR\ELS\svBuilder-Pro
3) Restart svBuilder-Pro
Also, the 'Troubleshoot AIR installation | Mac OS' page may help: http://kb2.adobe.com/cps/902/cpsid_90205.html
See the section entitled 'The user interface / window does not appear when running an Adobe AIR application, the Adobe AIR installer, or the Adobe AIR uninstaller.'.
SimpleViewer Support Team