We have been noticing a few cases where EPIC doesn't work on IE 11. When IE 11 was first pushed by BigFix, we did receive several calls from users not being able to login to EPIC in IE 11. The quick fix was to set the EPIC website to Compatibility Mode. Recently, this fix has not worked.
I was able to fix this issue on Vivek Bhalla's computer by:
Uninstalling the Citrix receiver
Rebooting (You must reboot)
Reinstalling the Citrix receiver
The funny thing is that I reinstalled the same client version but it worked on the 3 browsers, IE, Firefox and Google Chrome. Please try this fix and report back if you run into this issue.