This is usually because of naming conflicts, so if you have a script called Blah.js and a script called Blah.cs in the same project directory it'll do this when you build. Look for imported script packs or old scripts hanging around. Good luck!
Since your asset-files first character is a binary "0" (that'S what the error tells you), i guess the asset file is simply corrupted. Actually having a file called sharedassets0.asset in a Unity project seems a bit strange. I would guess you try to use assets from a different Unity-build. Are you sure that is "your" asset or that you are allowed to use it?