Bug

OK: Uninstall and reinstall again, and this time check the option to delete all preferences. Go into the user account and delete the whole Photoshop folder there to be sure (C > Users > your name > AppData > Roaming)

Worst case, you may need to run the CC cleaner tool to remove every trace of the old install. But maybe that's not necessary.

Unexpected end of file is a corrupt file. The question is where and which one.

When Photoshop starts, it loads in two parts. There's the read-only program files, and then there's the current app configuration which is stored in your user account in the preferences folder. Deleting this returns the application to clean out-o-the-box factory state.