I right clicked on search results and selected Open as Editor Window. The window opens as expected, but every time I click in this window an empty Preview window pops up. I do have Search results enabled in the Preview Tool Window.
SlickEdit Pro 2016 (v21.0.2.0 32-bit)
Build Date: February 23, 2017
Emulation: CUA
OS: Windows 7 x64
OS Version: 6.01.7601 Service Pack 1