Can not delete link from a slide

I am running a website that has been using Views slideshow for awhile with little problem. In the last few weeks there is some delay when we update a page. 2 days ago I deleted a slide and the link part of the slide remains. When I try to update the page I get the error message "The form has become outdated. Copy any unsaved work in the form below and then reload this page." and when I click the link for reloading, nothing changes. When I try to redelete the slide I get the error message "The requested page "/node/440/delete?destination=admin%2Fcontent&render=overlay could not be found." I can not find any recent discussion of this problem and don't know where to look next. Any help would be appreciated. The website is doorcountylibrary.org