As it is about fast travel check your addons that got to do with travel and wayshrines.
Which of them were updated recently for you -> Maybe the cause.
Or use a tool like Notepadd++ and search (menu search -> in folder) in your folder live/AddOns for "HookChecker" to find the causing addon.
How to find the live/AddOns folder:
https://www.esoui.com/forums/faq.php..._howto_install
If you found the addon write to it's comments about the debug message you always see there.