I assume you are clicking on a mobile link in your email client. Does the document still exists in your Laserfiche repository or maybe it has been deleted? No special privilege is required and if the user account used lacks the rights to the target entry you would get "Access denied". If the problem persist please open a support case as there are too many variables to effectively troubleshoot here (like is the LFMobile app running when you click the link, are you logged in to the repository that the link points to etc.)