customer's web mail launches only in lite/basic mode

Issue: customer's web mail launches only in lite/basic mode

more info: customer is using internet explorer. Customer checked in with admin and he/she checked and confirmed cas mailbox is set correctly

cause: customer had checked the "blind and low vision experience" option. If checkd, users get a very limited version of high-contrast web access, seemingly even more limited than the actual Light mode login. 

 Resolution:  Instructed customer to  uncheck the option, after logging in, under Options -> Accessibility.  The Outlook web Premium mode was back