Photoshop Elements 6.0, why can I no longer open it

I have had Photoshop Elements 6.0 for many years and it has worked fine. I have Windows 10 installed since one year back and it still have been working without problems. Then suddenly  a few days ago I could not open my Photoshop. I got the following message: "Standard catalouge not found. Open or create a second catalouge". All pictures are stored on my computer and not in the cloud.  What do I do?