My LG Optimus F3 4G. I recorded a video last night on my camera and played back with no issue but now when attempting to play I am getting an error message stating the file format is unsupported. How could that happen when I recorded it with the device cam and more importantly how can I get the video to play?

Hi
This is a phone rather than a camera, but the issue could be the same. Videos and Photos are usually saved to the SD card that can be removed and there may be options that you can try.
First. Turn off the phone power, wait a couple of minutes, remove the SD card, and re-insert after 10 secs or so. Turn the phone back on and see if the card is recognised. If so you should be able to get to your video.
Second. When you have taken your card out of the phone, use a card reader connected to your computer, and use File Explorer (Win 7) or Windows Explorer ( WinXP) to view the content of the SD card. It will show up as a removable drive. If it doesn't show up the card itself may have failed.
Third. Most phone manufacturers have software and cables to connect phones directly via USB to a computer. The software is usually downloadable, and the cables are getting more standard (Normal computer USB to micro USB for the phone end). Again the SD card contents and the phone contents should be accessible from the PC.
If these all fail, it is likely that your card has become faulty. You can try reformatting it whilst it is attached to the computer but of course this will lose all your data unless it s backed up.
I would always recommend getting the latest software for your phone from the manufacturer, as it normally gives you synchronisation options for contacts, diaries etc, backup options for your phones entire contents, and a means (usually easy) of transferring data, music, pictures, videos etc etc from phone to PC and vice versa.
Hope this is helpful, if so would you please register that with Fixya
Cheers