Are you using the cloud mod? If you are using any version of the cloud mod before 2.8, or if you aren't using the mod, there are a few WOFF clouds that can cause the ME to hang.
Also, make sure your version of the ME is up to date. The latest version is 1.4.8, I think.
Last edited by BuckeyeBob; 12/22/17 08:29 PM. Reason: 2.7 changed to 2.8