Clarity PPM might stop working in several scenarios in Internet Explorer (IE11) :
This issue is caused by the Defect DE42037
CA PPM 15.4 SP1 (15.4.1).
Does not occur in CA PPM 15.4 base.
This bug is fixed in 15.5 and higher and in 188.8.131.52 (15.4.1 patch 1) (184.108.40.206 01 17)
Workaround: Use a non IE browser (Chrome or Firefox) in the meantime.