I created a page and then I added a Web Part to the page. When I came back to the page to make edits, the Web Part was gone. I added a new Web Part but it's default name ends with , which makes me think either the previous Web Part is still there somewhere or the name is getting messed up for some unknown reason. Does anyone know why this is?
try opening the page and adding ?contents=1 to the end of the URL to get to the WebPart maintenance page. There you can see existing WebParts. Try referencing this solution