I'm so sorry, I missed your post when you sent it. I did finally realize that the Catalog-2-2.lrcat was the old copy, and removed it from my "Pictures" list.
Thank you for the detailed link for me to solve the problem of error 126. In Library, when a video is selected Lightroom crashes. I found if I work in Develop, I have no fear of crashes, since video doesn't work in Develop.
Thank you for your help WobertC, I so appreciate your responding to my questions.