Posts don't display after moving servers

[James Gryphon]

As part of the prep for a forum merger, I decided to set up my secondary forum on the same site as the primary. Everything works great for the most part, but this irritating bug with posting has stymied me.

Whenever I load a topic, the attachment below is what I get. No posts show up. All the FTP files, aside from the tweaks necessary to access the database, are the same as in versions of the forum that work, so it presumably has something to do with the migration and things like what's in the database. I've used repair_settings.php, emptying cache, and a bunch of other things, but I can't figure out what the problem is, and I'm starting to get very frustrated. I'm doubly so because it seems like I had this problem before while doing a trial run of the merger process and was able to figure it out, but now I don't remember what it was.   

If anyone has any suggestions as to what could cause this, I'd greatly appreciate it.