Whitelisted HTML tags are allowed in Markdown, but it seems that less are supported or they are handled differently now. For example, see https://sourceforge.net/adobe/flexsdk/wiki/Flex%204/ This probably happened when we upgraded Markdown recently. Check to see if its feasible to re-instate this support, particularly
<div> tags with some styles which are useful for layout. If it's not practical, we don't necessarily have to do it.