When I click on a mailto link, Firefox asks me what application I want to use to handle it. When I select Windows Live Mail, an error pops saying: wlmail.exe - System Error The program can't start because WLDCore.dll is missing from your computer. Try reinstalling the program to fix this problem. This error only occurs when trying to open mailto links with WLM from Firefox. Opening mailto links in Edge and Chrome open Windows Live Mail without issue.