Thank you for providing all the info and files, it's been very helpful. We have found that one of the campaigns in this save file is corrupt, and that is preventing the game from launching correctly. Unfortunately, the corrupt file is your main campaign. We have a few steps to help you try to work around this issue!
- Restore your copy of the HarebrainedSchemes folder to your AppData/LocalLow Location (keep a copy somewhere else just in case!)
- Open the HarebrainedSchemes folder and go to HarebrainedSchemes\LamplightersLeague\Save\Sync
- Cut the file user.hbssettings file and paste it somewhere else as a backup.
- Launch the game
This should get you through the Press Any Key phase of the main menu, but it won't help the corrupted campaign file. To address that, we strongly recommend launching the game with cloud-sync enabled, to see if an uncorrupted version of your campaign is available there!