SpamBlacklist uses $messageMemc as its cache which is set to deprecate in 1.35 and be removed in 1.36. I was dumb enough to check out 1.36 when it was alpha so I had to manually make this change. Strongly suggest the devs switch to $wgMemc and/or maybe use an existence check. For poor saps like me, simple fix is to sed -i s/messageMemc/wgMemc/ extensions/SpamBlacklist/includes/BaseBlacklist.php
Topic on Extension talk:SpamBlacklist
Also thought I should note, the error you get with this appears infrequently when the spam filter is triggered, and the message
<code>BaseBlacklist.php: Call to a member function get() on null</code>