Thanks for the detailed report - the exact error text was a huge help.
Found and fixed it: it was a compatibility issue between a couple of the bundled Python packages (torch/diffusers), unrelated to your checkpoint - it crashed the app on startup before it ever got to loading anything. It's fixed in the next update.
Separate thing I noticed while digging into this: it looks like you may have been using a Pony checkpoint. Just a heads-up in case you try it again - this app currently only supports SD 1.5 checkpoints, not Pony/SDXL (also noted in INSTALL.md under "Image checkpoint"). An SD 1.5 checkpoint from Civitai (filter by "Base Model: SD 1.5") will work correctly.