In Patch 11.0, InterfaceOptionsFrame_OpenToCategory was removed and replaced with Settings.OpenToCategory. Changing line 284 in AceGUI/ChoreTracker.lua to the following will bring the addon up to date and fix an "attempt to call a nil value" error:

settingsButton:SetScript('OnClick', function() Settings.OpenToCategory("ChoreTracker", self.optionsFrame) end)

Closing this as fixed with recent update. Thanks!