Simply uninstalling the AJA Adobe Plugin for After Effects didn’t fix the issue for me, it actually seemed to make it worse, since I couldn’t output anything.
I was directed by AJA to install the older driver (10.4.4) without the Adobe plugin, and it worked! Back to normal. They know there’s a bug in 10.4.5 that prevents After Effects from working properly with it, so they’re working on it for 10.4.6. So for now, install 10.4.4 without the Adobe plugin (if you’re using Premiere, go ahead and install the plugin for Premiere, no problems there).