You could reinstall NetFramework and see if that repairs the file. If you knew what was missing you could just reinstall that program. And then install all the accessory programs that the system uses. 11.17 Issue - Body Replacer - Fallout Character Overhaul aka FCO not working or conflicting. It is possible that the easiest fix is to reinstall Windows from scratch. 10.15.1 TIP - Fallout New Vegas Game Engine Bug List. I am not very familiar with all the files that can get corrupted in the Windows environment so I can't be of much help. These files are installed as accessory files provided mostly by Microsoft to run special programs in Windows. Most responses identify it as a missing 'package manager' file. Microsoft forums identified it as a NetFramework file. It is used for developing a range of applications, from simple desktop programs to applications for distributed environments. I typed '1keyebww.0.cs' missing into my browser and Steam identified it as a missing map file.Ī CS file is a source code file written in C#, an object-oriented programming language created by Microsoft for use with the. I do not think they are files that could be replaced by a repair to the system. I do not know what needs to be installed. As I pointed out, the error message says that you are missing system files.