Symptoms

I get an error "Multiple Authentication attempts detected" when I try to open my designer on IE 11, yes I have added it to trusted sites and enabled compatibility mode. Not using SSL, No SharePoint

Workspace have no problem working on IE, Chrome and FireFox also opens Designer.

Tried IE 9 as well with similar result as IE11.

My URL looks like the following:

http://K2_dev.casey.vic.gov.au/designer and gets redirected to "identity/sts/windows" see attachment

 

Diagnoses

The issue occurs when IE tries to hit k2_dev url instead of k2dev(get multiple authentication error)

 

Resolution

The fix was to edit hosts file - adding host entry, changed k2_dev to k2dev
Then a change to iis to force ip to resolve

In house, "As suggested I put a CNAME without the UNDERSCORES into our domain DNS and the issue has been resolved".