5K Retina iMac can't open Image Sequence quicktime 7 Pro and 10.10 Yosemite

I have this with a very recent Mac Mini. About 120 jpgs trying to do 10 fps and QT Pro just simply crashes in Yosemite. Pretty pathetic - and I only bought QT Pro licence for its "supposed" ability to do quick time lapses, having found the latest iMovie to be pretty pathetic at this. Having tried two Apple software products and having found it a miserable waste of time I will take the hint and buy something elsewhere.

Based on the lack of specific information here, it is unclear if you are seeking help or a place to post a rant. In the event it is the former...

1. I have posted a "quickie" screen recording demonstrating the QT 7 Pro "Open Image Sequence..." workflow under Yosemite to create a 133 random image Photo-JPEG MOV file with playback frame rate of 10 fps. This clip then demonstrates playback of the newly created file: SAMPLE FILE
2. If QT 7 Pro is crashing, then something is wrong with your system, the QT 7 Pro app, or your workflow. For instance, if the player only crashes while woring in one user acount but not another, you may have a corrupted QT 7 PLIST file for the affected user account. On the other hand, if the problem is global, you may have a bad install of the base QT 7 Player software.
3. While your MacMini may be new, the QT 7 Pro Player is itself a legacy app (which is being replaced by the more modern QT X Player software) and was not intended for use much beyond HD resolutions, image sequences greater than 65535 images, or really high data rate throughput (as a related consequence of over-sized JPEG images).
4. Since you did not mention the dimensions of the JPEG images you were trying to sequence, I suspect this may be your primary problem. HD images (16:9) are 1920x1080 pixels, 2K (4:3) 2048x1536, 2.5K (4:3) 2560x1920, UHD (16:9) 3840x2160, and 4K (4:3) 4096x3072.
5. Since most 5K Retina and most non-Retina monitors are, by default, limited to a max 2.5K display resolution, this would likely be your max target resolution for best cross-system compatibility when generating image sequence files. Anything larger is overkill and likely to create problems such as crashes or an inability to render the sequence files during playback even when the app does not crash.
6. As you can see, any of today's 6MP or greater digital camera formats already exceed this target resolution and the 2560x1691 Photo-JPEG file created during the recording of the above SAMPLE FILE screen recording topped out with a data rate of nearly 120 mbps or roughly the equivalent of playing 4 (VC-1) to 6 (MPEG-4 AVC) Blu-ray discs simultaneously.

In short, without knowing more about what you are trying to do and how you are trying to do it, it is impossible to say if your current problem is normal and to be expected or not.

Since you did not mention the dimensions of the JPEG images you were trying to sequence, I suspect this may be your primary problem. HD images (16:9) are 1920x1080 pixels, 2K (4:3) 2048x1536, 2.5K (4:3) 2560x1920, UHD (16:9) 3840x2160, and 4K (4:3) 4096x3072.

I was having the same issue with QuickTime Pro crashing while attempting to create a new time-lapse image sequence from a series of 265 jpgs.

I finally found this thread and read through the responses. After reading your response, I realized that the images I was attempting to open were 5184x2916, set for 16:9.

I ran a batch process through Photoshop CS5 and resized all images to 1280x720, and lo and behold, the sequence opened in QuickTime Pro without any issue.

Thank you for your detailed replies in this thread. They were a tremendous help.