Running the latest version of CFB on client and server (6.3.26) with Forge 2364. Intermittently getting a Rendering Block Entity crash on login when the pots and pans from Pam's Harvestcraft are in the oven's inventory. The crashlog is appended.

crash-2018-03-30_20.49.38-client.txt

Try updating your Forge, I can't reproduce this crash and it doesn't make any sense if not for a bug in an older Forge version.