Windows 10, latest Java, LRTimelapse 4.5.1.

Editing a 630+ frame timelapse.  I get all the way to the Visual Preview stage, and when I create the visual preview, I get a purple frame that corrupts the original file.  If I open the file in Lightroom or even Photoshop the file has purple digital tears.  I can replace the individual file, but then another becomes corrupt.  I've replicated this several times, each has corrupted a different frame.

I did change the available threads recently, so I returned it back to 4, and got perfect results.  I have 6 cores, 12 threads on my intel i7 3930K system.  

It's a bug, but luckily it's avoidable if you just stick with the default settings.  This stumbled me for a few hours...

First: LRTimelapse does not corrupt or even touch any raw files. LRTimelapse only works on metadata.

What LRTimelapse does is creating previews, the visual ones are actually being created using the Adobe DNG Converter. Do you have the latest DNG Converter installed? You'll find the download link on: http://lrtimelapse.com/install
If a RAW file is corrupted (maybe the drive with your images is not okay?) you might get a weird looking preview. But still - the RAW file is the original one, no touching there by LRT.

Since you said that exchanging the RAW file makes another one looking corrupt, I assume it might be something with your drive. So try to copy the files to another location then start over completely (right mouse on folder in LRTimelapse -> Clear all LRT Editing). Now just turn on the visual previews (no editing, no Lightroom). Does the problem persist?

Interesting thought.  My storage system is fairly new, so I'll do a quick check on an SSD.  I'll also go back and verify the dng converter is up to date.  

As a note, I would clear the meta data, and the raw file that seemed corrupt still didn't display properly.  I even restarted all software to ensure it wasn't a cache issue and yet the same problem.

The only thing that prevented This from happening (on my storage system, and not tested with the SSD mind you) was switching the dng thread count back to 4.  I'll experiment and let you know if any other setting result in the same event.

A note: I was able to get the timelapse exported and preview just fine with my storage when I switched to 4 threads.  

I'll report back with any new findings in the coming weeks.

I assume it's only the previews that break, you can force LRTimelapse to renew them by hitting "Shift F5", you can even make a selection before. Try, if that fixes the broken previews.

On a side note: I always work with 8 threads and have never experienced this.

I'll try the refresh idea and the 8 threads in my testing as well.  Thanks!