With a recent update, Microsoft upgraded to Internet Explorer version 11. The most recent version that is officially supported by IACRA at this time is Internet Explorer version 9 (Although it does appear that IEv10 does work).
At this time there is no determined time frame available for when (if) IACRA will be able to be updated to support use of IE11.
It is encouraged that users consider carefully any update to IE11 if they will need to use IACRA on their computers. This is pertinent to applicants, instructors, and examiners who need to use IACRA for airman certificate processing.
An alternate option that does still appear to work is a current version of Mozilla Firefox.
Please plan appropriately when in need of airman certificate application and processing.