It is necessary to correct the processing of file "Morrowind.ini".
Text language localization in "Morrowind.ini" after running "MGEgui.exe" are corrupted.
To correct it you should specify the second parametre "Encoding.Default" (in the file "INIFile.cs"):
sr = new StreamReader (File.OpenRead (fileName), Encoding.Default);
sw = new StreamWriter (File.Create (fileName), Encoding.Default);