Since I’ve upgraded my machine from Windows® 7 to Windows® 8 (and recently 8.1) I have had a few related issues with Windows Store apps (i.e. those Windows 8 specific apps that could start in “the Modern UI area”, i.e. not on Desktop):
- Some apps didn’t open or run successfully (event after reinstalling, Windows Store repairing, App troubleshooting running, etc.):
- Bing Translator didn’t open at all;
- Skype app worked well on Windows 8, but didn’t open at all in 8.1;
- Kindle didn’t start or couldn’t download books on the local storage (could only read books online);
- Local libraries couldn’t be successfully read from Store apps (although they was stored locally and not on external drives, being correctly indexed and always available from Desktop mode and Desktop apps such as Media Player, Photo Gallery, and Zune):
- The Photos, Music, and Videos apps available by default haven’t been able to load library content; they all reported “It’s lonely here” messages, suggesting adding new items to the libraries (except for Photos app on Windows 8.1 update, which did read and presented local photos correctly.)
- URLs didn’t open the browser when links were clicked inside Store apps; the links looked as clickable, but clicking them didn’t do, virtually nothing; this was true even for Web site links inside the original Windows Store app (both in Windows 8 and after 8.1 upgrade).
The resolution (suggested in this Microsoft Answers thread) for all these issues was to use Regedit (from all affected user profiles) and delete this key: HKEY_CURRENT_USER\Software\Classes\CLSID (make a backup first). After signing out and back in (even without reboot), all Store apps open and run correctly, library items can now be read and presented by apps relying on them, and URLs start open the browser when links are clicked inside apps.
Note that deleting the CLSID key from HKEY_CURRENT_USER will clean up the current settings for the current user profile only, and will not affect the entire machine settings. (Finally, I’ve actually re-added some of the keys in the backup of the CLSID, i.e. only those with keys with non-empty values on their sub-keys, and everything still works, and I have no fear that any real personal settings are removed.)
Update: Unfortunately the issue may reappear after Windows or other product updates, at least on the same machine and under the same user profile, so be prepared to redo the steps above whenever such a regression occurs.