In 2025 I have a file where I am trying to copy pages into another file and I get a pop up message saying "Cannot modify elements that contain locked content, or are contained by locked content. Please unlock or check out the content and try again." This makes no sense, I have never seen this before. There is NO reason for (as it turns out) having a locked object on a page to preclude me from moving/copying that page, this is isnane.