As in the title. If I unplug my internet connection, the game crashes at startup, but if I plug it back in, no problems.

Done this more than once. Modded, unmodded, uninstall and reinstall. All the same. No internet=no gameplay. What the actual fuck is this sorcery?

Same here

Whelp, I'd LIKE to try to chase down what may be the reason for this, but a fresh install doesn't seem to help.

Mostly because fresh installs are now failing. On ,both my machines. So yea....can't really test things if I can't install your new update.
*edit for spelling

they're spying on us