If the following appears regularly then it is possible that browser settings are hindering proper display.

[Confirmation Method]
Safari Browser → Environment Setting → Privacy → Cookie & Web Site Data
If “Always Block” or “Only Allow From Currently Accessed Web Sites” is set, it’s possible that the program will not function normally.
If an error is displayed with “Allow from accessed web sites” then please see the following link: http://salesforce-app.makeleaps.com/ and then access the ML4SF page again.