Forgetting to click the SHOW button. Cards are saved for only seven days, generally, though you are welcome to see if it is still online even after seven days. If not a timing problem, there is an error in the Directory or File Number. Highlight the 9 Number File Code on you announcement by pressing down the left mouse button while you scroll your cursor over the code. Though most people find Card Pick Up easier, if you prefer, you can go directly to the card's direct WWW address.
Small letters are different from caps.
Be sure there are no spaces before, within or after. Do NOT use the direct URL at Card Pick Up. Highlight the card URL by scrolling over it with your mouse. Be sure only the URL is highlighted. Click in the Location or URL box on your browser.