There is a known issue affecting Internet Explorer 11 that may cause FMX to be unresponsive if you use Active Directory Federation Services (AD FS) or Single sign-on (SSO). Note: if you use Internet Explorer 11 with other sites where you use AD FS or SSO, they will be similarly affected.
To fix this issue, you will need to deploy the optional update from Microsoft found here: https://support.microsoft.com/en-us/help/4343894/windows-7-update-kb4343894
This issue should be temporary until Microsoft rolls out this update to all Windows 7 users.
If you’re still unable to log into FMX using AD FS or SSO after deploying the optional update, please contact our Support team at firstname.lastname@example.org.