Issue with reopening the Negative Lab Pro editing panel

I applied Negative Lab Pro roll analysis to a total of about 80 images in Lightroom, with a minimum of 2 and a maximum of 6 images at a time. However, when I open Negative Lab Pro again, it only analyzes the metadata without opening the editing panel. Even after restarting Lightroom, the same issue persists. Does anyone know how to resolve this problem?

…can you add a screen capture of how that situation looks?
Plus details about the versions of NLP, LrC and OS you use?