Huh? How the hell did that happen?
I have never encountered anything like this (i had broken packages in status, but i could manually clear them from it as a last resort, but never ever an empty status or available files).
You should post what you did exactly.
A possible workaround is detailed here:
The idea is to put a character (an empty character is enough) in the file (both status and available) because they are really empty (dont contain any character at all), they might not be repopulated.
echo "" > /var/lib/dpkg/available
With root rights.
Let us know if it works (or not).
PS every command related to these files needs root rights (sudo).