Pages Missing from the Last Scan

When optimizing a page using the "Optimise your page Feature" I get the error message "The page was missing from the last scan"?

This happens when you change the URL address of a page. In these cases you just delete the page from the list in the Optimize for Search section and re-add it with its new URL - Since you were initially optimizing it under the previous, 'old' URL, once you modify the page URL, MarketGoo is still searching for it and says it's 'missing' from the scan. 

You either need to choose if you will retain the page or remove and re-adjust the new page you have altered.