These items won't download because they are built-ins from TS12, eventually they maybe, but not right now. You can import them and then run PEV's Images2TGA to convert the .texture files, which are causing the error.
You may have issues, I can't remember offhand now, with the engine-spec, which also needs to be fixed. One of the new things in T:ANE is integer versus real number values. Integers are whole numbers, while real numbers can have decimal values. I think this might be one of the issues with this engine-spec.