When clicked from two different locations (the Task Bar and the Desktop), icons that have legitimate URLs will not automatically open and display in the default Firefox browser. To test, I have changed the default browser to IE, but the same thing happens, nothing: there is a momentary hourglass appearance but no webpage is displayed. Firefox is listed as the Default Browser for all other extensions (.com, .htm, .html. etc.), yet no webpage appears when links are clicked outside of the browser itself.
Links do appear as webpages if they are 1) copy and pasted into the browser's address bar or 2) clicked within the browser.
Since this has previously worked successfully, I surely did something wrong. Woe is me. Where to start...?