Sorry to hear about this problem, @Andy!
I cannot recreate this issue, and we don’t have any other reports of it at this time, so I would recommend the following steps:
1. Deactivate the “Root Relative URLs” plugin on your site.
2. Go to Settings → Permalinks in your site’s wp-admin. Click “Save changes” here without actually changing anything; this will just refresh the permalinks on your site.
3. Go back to the settings page and see if the issue persists.
4. Try going to the /events page on your site and see if it is inaccessible.
5. If the issues persist in steps 3 and 4 above, then leave “Root Relative URLs” deactivated and proceed doing this same process for EACH other plugin on your site: deactivate a plugin that is not The Events Calendar, do step 2 here, then do steps 3 and 4 to see if issues persist.
If you get to the point where The Events Calendar is the only plugin activated, and these issues persist, let me know!
Thanks,
George