When attempting to map SharePoint Online to a local drive letter, you may encounter the following error message:
The Mapped Network Drive could not be created because the following error has occurred: Access Denied. Before opening files in this location, you must first add the web site to your trusted sites list, browse to the web site and select the option to login automatically.
There are other steps that may be required to successfully map SharePoint Online as a local drive letter. The following link discusses the most common issues and solutions: http://nikpatel.net/2014/12/23/mapping-network-drive-for-office-365-and-sharepoint-online/.
Note: Be sure Office 365 is installed and configured on the machine running LinkFixer Advanced, and that your Office 365 user is authenticated to SharePoint Online using Internet Explorer. Authenticating to SharePoint Online using Firefox, Chrome or another browser is usually not sufficient to allow the necessary drive mapping in Windows.