First, version numbers are separate from service release numbers.
AFAIK there is no QlikView 11.4, but there is a version of QlikView called 11.20 SR4.
Are you upgrading from QV 11 SR2 to QV 11.20 SR4?
If so, then it's mostly an in site feature upgrade without too many things to watch out for. Service Releases on average pose not risk whatsoever when perfomring an upgrade (except for the first SR4). In addition you could look at 11.20IR as 11.00SR3 with added features.
Can you post the correct version numbers? Thanks.