redfoxrommy

Locate the modpack folder, open the config folder, open the forge.cfg file and edit the values for "Remove erroring TileEntities" to true. Save and try again.

It appears, from the MD5 error and failure to download anything, that you have an antivirus or firewall blocking the launcher's activities.  You also have a Buildcraft pipe blowing up your world, possibly from updating mod or modpack versions on an old world.  I suggest an MCEdit solution or world reset.