Today I upgraded to 11.3-U2. The process went smooth with the exception that some UI functions did not work. I have had similar problems after 11.3-U1 reported in
NAS-105087 now closed and duplicate to NAS-104277. I fixed the issue by clearing "site data" in the browser and refreshed the page and everything was fine. No problems for me.
My suggestion is to mention this in the release notes until the bug
NAS-104277 is fixed. I understand that all known bugs cannot be mentioned in the release notes but in this case I feel tht it undermines the user's confidence in the upgrade. The users that may not know how to debug/work around similar issues are the ones that need this the most. These users could easily be left with the feeling of "this is crap and I will use some thing else...".
Just my five cents.