Quicktime 50 error on send to compressor from Final Cut 7.0.3 on OSX 10.9.3

Quicktime 50 error on send to compressor from Final Cut 7.0.3 on OSX 10.9.3

Hello :-)

For several days now I have been unable to successfully compress anything using compressor when sending from Final Cut Pro. I read on another forum to tick the App Nap box on Get Info on Applications<Final Cut, but this has made no difference. I get a Quicktime error 50 message. Have made sure that my computer is unable to go to sleep or go to a screen saver but this has also not helped. All suggestions greatly appreciated. And yes I am very attached to Final Cut 7... I really hope that this is not the start of the inevitable demise of FC7 on my newish computer.

Cheers
Wanda