I received an error report for the marriage of Kimmich-28 and Kühner-20, indicating a spelling error in the marriage location. The location was listed as Altdorf, Nurtingen, Wurttemberg, Germany. Elsewhere in these profiles the location was given as Altdorf, Nürtingen, Württemberg, Germany. I assume that the spelling error was the omission of the umlaut in Württemberg, and I corrected both Nürtingen and Württemberg.
The spelling Wurttemberg is not correct. However, considering that the source cited for several locations in the profile was familysearch, and the familysearch index records (no images available) do not include umlauts (for example, in one record, this placename is given as "Altdorf (OA Nurtingen), Wurttemberg, Germany"), I am not convinced that it's productive to flag the omission of the umlaut as an error. As I understand it, the omission doesn't inhibit the ability of most search algorithms to find the record, but nagging contributors about the omission of the umlaut is likely to frustrate people who thought they were "doing the right thing" by relying on a record to generate their information.