Not a valid map file

[jonny2027]

I have just opened my latest map today to be greatest by the error message xxx.udk is not a valid map file.

I originally created the map in the feb 2012 release then yesterday opened and worked on it in the march 2012 release having saved it last night the backup ran so both my local and my backup copy now come up with the same error.

Does anyone know if there is anything that can be done?

Thanks

Jonathan

[jonny2027]

Thank goodness for auto save files