@nnnn19 hello and thank you for taking the time to get back to me. I tried what you said and it seems to be working now. Very strange though and I think that page with the video should be updated with a FAQ for others who are having the same issue.
Also I wish there was a way to do a full backup of Opera including all plugins etc like I can do with Firefox (just copying the directory) as it is such a pain to have to go and reinstall all the extensions again.
Nonetheless thanks for your help.