Finally got around to upgrading to 1.1.1 today on vB4.2.1, and I'm having a very strange error. My users and staff (including moderators but not including admins) cannot access their notifications or profile pages. I had updated several other addons in the same session (all DB Tech addons: Advanced User Tagging, vB Arcade, Username Change and AJAX Threads), but we've confirmed the error did not crop up until after this addon was installed.
The error only happened after this addon was updated, but did not seem to vanish when the addon was disabled/uninstalled.
EDIT: Hmmmm. Looks like it may be an addon conflict with
Tournaments, Ladders & Leagues Manager v4.x. Disabled that addon, and now it's working again. Don't know how the heck that error could stay there even when I'd disabled/uninstalled vBSecurity, but since it only cropped up after updating this...*shrugs*