Your organization has selected Zscaler to protect you from internet threats.

Sorry, company policy prohibits this action.

Website blocked
Network app HTTPS Application service asvc_non is Blocked by Firewall rule Global Blacklist by Destination

Your IT department is blocking syncing (but apparently not error reports).

https://www.zotero.org/support/kb/zotero_and_firewalls

(Someone else from your company reported this the other day.)