No valid security key found. Please use at least the following shortcode:
[advanced_iframe securitykey="<your security key - see settings>"]
Please also check in the html mode that your shortcode does only contain normal spaces and not a instead. It is also possible that you use wrong quotes like “ or ”. Only " is valid!
Support for older versions of Internet Explorer ends on January 12, 2016 What is end of support? Beginning January 12, …