OK -- I FIXED IT.
Through a lot of trial and error.
Head to users/user/appdata/local/microsoft/windows/applicationshortcuts
Once there do a search for each file within application shortcuts using the search bar in the top right of the explorer, you might need to play with the search terms. For example, mine found the photo app when I searched 'modern' but not 'photo'. Odd.
I used the following terms, camera, microsoft ((for skydrive)), bing, modern.
You need to delete the little white shortcut tile (I had to adjust security settings first and give myself permission to delete within the app shortcuts file, but Windows will guide you through it.)
For the chat app, just delete and reinstall the calendar/people/mail group and its gone.
Hope it works for you guys too...
*FIXED WITH A DIFFERENT SOLUTION* (for me anyway) - Open Internet Explorer via desktop link (NOT the tile on the Start page), click Tools, Internet Options, click the (Brower-History) Settings button. If the "Current location" is blank, then click the
[Move folder...] button and select/save to a known valid location.
To recap, after I upgraded from Windows 8 to Windows 8.1, I experienced a problem with many of my Start page tiles being broken (the apps did not run). I tried the fixes suggested but unfortunately they were unsuccessful. While using Windows Explorer, I
discovered that my G: drive (AMD RAMdisk) was gone (I had installed this while I was running Windows 8), and this gave me the clue to check my browser settings, since I had previously set both IE and Firefox to point to the G: drive for their temporary internet
files. After fixing the RAMdisk issue (reinstalled and rebooted), I opened the Internet Explorer via the desktop link (NOT the Start page tile), and discovered the "Current location" of the Temporary Internet files was blank. Once I fixed this using the
[Move folder...] button and saved the settings, the Internet Explorer tile worked again, as did the previously broken app tiles.
NOTE: Apparently, the Internet Explorer tile relies upon a valid Temporary Internet files location to work correctly, but the Internet Explorer desktop link can work without it. Also, it appears that the Temporary Internet files folder is also used by
many of the app tiles on the Start page. Once the Internet Explorer tile was fixed, every app tile with a broken link started working. After I clicked on the first broken app tile, it did a quick "download" and then opened - the rest of the app tiles automatically
fixed themselves. Hope this helps!