is it just me, or are others having problems as well with the RSS feed of the MaxMSP forum? Strangely, my RSS subscription for the Dev forum works fine, it is only the MaxMSP feed that stopped working some two days ago in Mail. I get the `The feed could not be loaded because the content is not in a known feed format.’ message.
this sometimes happen to me too, like those last days. It’s often because someone used some special character (sometimes invisible) in a post, which is refused by your RSS software. You have to wait until the message is not in the feed anymore. If you use Thunderbird under Mac (which is my case), have a look into the error console, there is probably a "not well-formed" error.
There are already a couple of posts on this topic, ans I though it was now corrected… It may be something else.