When I read the post (assembly: what is the return value exactly doing?), the user mentioned that he had hit a maximum number of posts.
I looked at the help page but didn't find anything. The help is also not searchable, it seems, because when I enter a search it looks only in the questions, so it's not context dependent on where the search is performed (might be a good thing to have it context aware).
I found many posts related to questions asking for limits of other properties like edits, tags, and so on. Wouldn't it be helpful if the help section contains a chapter where such limits are documented?