Steam - Game content conversion

[nireth]

I tried playing P:BP today and received this message:

Steam needs to convert the game content for "Penumbra: Black Plague" to a new, more efficient format. This will require an internet connection and a few minutes' time.

So I give it a few minutes during which it attempts to reconfigure new content, but after that I always get the error message

Conversion failed (Connection timeout)

According to posts on the Steam forums I'm not the only one either, but they don't seem to have a solution so far, so I thought I'd try my luck asking here.