Final Cut Pro 6 loads then shuts off automatically. CAN'T OPEN APPLICATION. HELP.

Hi there

I have been working on Final Cut Pro here at work editing a very important film.

Everytime I start up the program, I receive this message:

Unable to locate the following external devices: Apple FireWire NTSC (720 x 480) Your system configuration may have changed, or your deck/ camera may be disconnected or tuned off. Please check your connections and click 'Check Again', or click 'Continue' to set external device selection to None.' clicked don't show again

Usually I just click "Continue" and allows me to work in the application regardless. It was working fine yesterday but now that I came in today, the message persisted when pressing either option and won't open the application. When I clicked, "Don't Show Warning Again," the Final Cut Pro loading message pops up but quits the application right after.

PLEASE HELP

The computer specs are and SHOULD be a very capable computer.

Model Name: Mac Pro

Model Identifier: MacPro4,1

Processor Name: Quad-Core Intel Xeon

Processor Speed: 2.26 GHz

Number Of Processors: 2

Total Number Of Cores: 8

L2 Cache (per core): 256 KB

L3 Cache (per processor): 8 MB

Memory: 16 GB

Processor Interconnect Speed: 5.86 GT/s

I have already tried deleting User Preferences.