[texworks] message from TeXworks user(MiKTeX)

[Katrin Schaar]

Hi everybody,

I´m trying to produce a pdf-file using MikTex.
Everytime I want to compile the file, I receive following error:

" You are attempting to make a LaTeX format from a source file that is 
older than 5 years."

I receive the same message, no matter if I use MikTeX 2.8 oder 2.9 
(which I just installed today, respectively).

Can you help me and send some advice?

Greetz,
Katrin