This sucks
i really wanted to try the new direwolf20. I still have the folder on my desktop but it has no mods in it nor can i find the pack on the launcher. Maybe reinstalling FTB launcher might fix it.
The reason for this is because direwolf20 (for 1.5.2), unleashed, and unhinged are/were all beta packs. You have to find the private pack code and enter it in the launcher (The codes are here:
http://feed-the-beast.com/disclaimer.php). All three are showing up on my launcher, plus I think they just updated the launcher, and they should show up at the top of the list today.
About those errors, every time I load a world I update the modpack (Unleashed in my case), re-select which mods I had, I still got those warnings. It didn't seem to damage the world to me, but I would still back up my saves anyway. If you aren't using OpenCCSensors (that's what OCS is) in your world, don't worry. Otherwise, find a way to add it back in, then replace whatever was from that mod with something else for compatibility.