Freeze issue in Windows 10 1803 when use UTF-8 as default code page
Windows 10 1803 (April 2018 Update) introduced a new feature, "Use Unicode UTF-8 for worldwide language support", it can be found in "Region" - "Administrative" - "Change system locale" - "Region Settings". When it enabled, Zotero will freeze after launch.
There've been numerous reports of freezing after the April 2018 update, which appears to be a general problem affecting many apps that was fixed in the latest version. So make sure you've updated to OS Build 17134.48 or later, and post to that thread if you're still having trouble.
No other app or program seem to be affected, for me it's just Zotero that misbehaves at this point. On the other hand, LibreOffice, which also picks up language settings from the OS locale AFAIK, works fine regardless. Needless to say, deselecting that option allows for Zotero to start normally too.