Instead of the old catalog appearing the Catalog window opens with the message "Choose a catalog". This began to happen after experimenting with Click and Tag. After reverting to prior saved C:\Users\Owner\AppData\Roaming\XYplorer things back to normal.
v14.40 is working normally otherwise. Have not done anything further with Catalog as it is again okay and don't want to upset things. Do believe there is an obscure bug lurking somewhere. Only recourse for now is to not employ Click and Tag.