Sometimes the settings that store the "layout" (position on screen, size of window panes, splitters, etc.) get set beyond where you can "grab" the edges/splitters to resize. This can result in the editor or ClipList panes becoming invisible.
This can be corrected by "resetting" the layout settings. To do so, go to Tools | Options | Advanced. There is a button titled "Layout/Font" under the "reset" section. Click that, re-start ClipMate, and all should be well.