SYMPTOM:
In Strategy Web 9.x, an HTML container configured to display a web page in an iframe gives a blank page when the Document is executed in Firefox. In IE, the iframe shows the error below :

Sample Code/Error
This content cannot be displayed in a frame.
To help protect the security of information you enter into this website, the publisher of this content does not allow it to be displayed in a frame.
CAUSE:
Like the error states, the website used within the iframe has disabled its content from being displayed within an iframe. This is a site specific setting and can only be changed by the site owner. This can be proven by testing other URLs within the iframe in a Strategy document, such as the Strategy home site: http://www.microstrategy.com
In Strategy Web 9.4.1, a new Clickjacking security feature introduced in this version may also cause this error if users attempt to embed the Strategy Web application in an iframe. More information about this setting is provided in KB45652: How to prevent Clickjacking in MicroStrategy Web 9.4.1 and above
ACTION:
Use hyperlinks to navigate to the desired website, instead of embedding it in an iframe, or, if using Strategy Web 9.4.1, disable the Clickjacking feature described in KB45652: How to prevent Clickjacking in MicroStrategy Web 9.4.1 and above