edit: tr.v., rigged, rig·ging, rigs. 1. To provide with a harness or equipment; fit out. n. (Abbr. CPU) The part of a computer that interprets and executes instructions.
Its your topology around the indent that is causing the triangle like shading error. In this case, having an n-gon to terminate the loops is giving you the error.
@ Zeist & cavuliero: Thanks for the advice. It worked! Everything imported correctly in the new blend file just fine. Thanks for the advice on the N-poles cavuliero. Cheerio