When you can launch the App Store, make sure Gatekeeper is enabled before downloading apps.
Open System Preferences > Security & Privacy then select the General tab.
Make sure either Mac App Store or Mac App Store and identified developers is selected.
If that area is grayed out, click the padlock icon to proceed.
Hi there Linc,
you are correct, I have used 'Clean my mac" and soon as I sa your reply, I immediately removed it as per developer instructions. I am sorry, I shall never again deter from the 'apple authorised' path.
Now that I have deleted the demonic application, I shall back up my data... This will be my first time so i am a bit nervous. I do have 16 gbyts left from a total hard drive space of 120 gbyts. Is this enough? How do I go abouts backing it up.
Thanks Linc. Or should I say, 'my saviour'....