Topic
When a user opens a Nintex Task Form, the page in the browser states "This [site-GUID].sharepoint.com page can't be found"
Instructions
This is a known issue.
SharePoint is not correctly XML encoding the FormUrl values in each content type definition when the list's content types are being updated (for example: new content types being added, re-ordered).
Additional Information
This is occurring on the SharePoint platform, Nintex has worked with MS on this but is unable to resolve this issue.