The way AdBlock and similar extensions work is that they look for keywords, such as
ad
advertisement
, this includes classes in html, including content as:
HTML:
<div class="ad">
text
</div>
As it is only but a tool, it is not perfect and thus it might also block content that the user might want to actually see - including a board named "Advertisement", which the tool understands as undesired content and thus it blocks it's visibility.
A quote from StackOverflow:
So this is not really an issue with OtLand, nor is it really an issue that OtLand could fix - simply disable AdBlock on these forums and you're good to go.