This is most likely an issue with IE Security.

Please add  to your safe sites within IE Security Settings.

Follow these steps - 

Open up your Settings within your browser - most have it on the top right hand corner of your screen 

Next - from the drop down listing choose - Internet Options

Then on this pop up screen - choose Security, Trusted Sites and then click Sites as shown below

Enter as a trusted site - and click ADD

Then click Close

Try logging in again and the issue should be resolved.