I’ve been using QT 7 Pro to export large (6800 x 768, 29.97 fps, 15 seconds long, no audio) uncompressed avi files for digital signage for years without any problems. Suddenly last week QT 7 will only export 1 second of the 15 second files.
The files are built in and exported from After Effects CC 2015 as uncompressed Quicktime files. I then use QT 7 Pro to export these files as uncompressed avis.
The only software update that occurred recently was an Adobe CC 2015 update.