I have a series of map that I created in ArcMap 10.3.1 that have many labels and annotations. To filter labels, I set parameters using Maplex label engine. I upgraded to ArcMap 10.4, and now when I open the mxd that I created in 10.3.1, none of the parameters to filter labels that I set using Maplex are reflected in the mxd. All of the labels are now showing and overwhelm the map. Is this a know problem? Do I need to recreate the mxd and labeling in the new version.
Continuous development on the Maplex engine means that there might be slight changes to improve placement quality between versions but nothing to the extent you are describing. Could you provide some further details of your issue? Screenshots of before and after if possible and any other information you think might be useful.