One of my users reported being unable to split documents in Laserfiche Scanning.  I witnessed the issue and was able to reproduce the problem on my machine (10.2.1.973).  When you scan a multi-page document and select the thumbnail, the 3 split document buttons are gray and Ctrl+D doesn't work.  However the split document button on the context menu does work.  See the three red circles and one green circle on the amalgamated screenshot.  This behavior continues until you double click one of the thumbnails, then the split buttons light up and work as expected.

After poking around I found the solution in an unexpected place.  Click File > Options, then under the Navigation category check the box titled: "Selecting a thumbnail updates the Display Pane"  This made the behavior of the UI consistent with the right click context menu.