H.264 defines many formats. Cyberlink does support only few of them.
Best results with: fixed frame rate, fixed bitrate, YUV4:2:0, 8Bit.
With any other format, there can be problems. So if you have footage from a more professional camera, that shoots in YUV4:2:2 or more) in 10Bit, than ColorDirector is not able to load that footage.
So try to convert your video clip prior to loading it to ColorDirector. Handbrake is the most recommended converter. And, unfortunately, you will loose color information...
Hatti
Win 10 64, i7-4790k, 32GB Ram, 256 GB SSD, SATA 2TB, SATA 4TB, NVidia GTX1080 8GB, LG 34" 4K Wide, AOC 24" 1080