After Effects won't render quicktime

Hello,

I'm trying to render quicktime files and recieve this - After Effects error: Rendering error while wriring to file . Unable to open file. (-1610153459)

My rig

i7 CPU 93- @ 2.800

2 x GeForce GTX 460

16 GB Ram

These are files which I've previously rendered without a hitch, this started yesterday. I've deleted folder in appdata with no success. I hope someone can help me as I've an irate client.