hello! Sounds like it's getting overloaded while trying to generate the thumbnails, but it's hard to say exactly why without logs. Those must be pretty large images then, or maybe just a large amount of them. I just tried it out with a few high resolution images (6K to 8K) and it handles it fine, besides being a little slow with zooming in and out

We'll try again in the weekend, could you leave some more info in the mean time, like the resolution and image types in the folder?

I'm also running into this with decently sized images - given a folder with a hefty enough amount of 5K-8K jpegs I can reliably crash the renderer process if I get them all generating thumbnails at once (though several parallel generations don't seem to be a requirement, I still get a crash eventually even after modifying the app to only run one thumbnail generation worker that only generates one thumbnail at a time.)

Turning on all logging options doesn't really clear up much, the crash itself is somewhere in Chromium/Electron - somewhere along the way the OffscreenCanvas approach likes to occasionally barf on large images, I believe it actually barfs in createImageBitmap from adding a bunch of extra console.debugs, but I can't really debug further without building Electron from source which is a bit of an ordeal. I did however try rewriting the thumbnail generation to use sharp, which not only alleviated the crashes but made it noticeably faster.

I then quickly ran into what you seem to have found before in #365 - sharp works fine in dev mode, but I ran into problems getting it working in a packaged build (at least on Windows.) This seems to be a known problem lovell/sharp#2764 - I found a possible partial workaround, now included in a PR, but there may still be a better approach here.