I can also confirm no issues of this nature with ISE 1.4.
I've used both Admin and guest portals at two different 1.4 deployments without issue.
Browsers FF39 and 40, Chrome 43.0.2357.132 m (64-bit) and IE 11.0.9600.17843.
All failed on an older ISE portal (@ Cisco office - I believe ISE 1.2.1-based) and succeeded with the 1.4-based ones.