Guys...relax... there's a fix for this.
I'm a STEAM user too... and you're right. It doesn't update itself for some reason.
Here's what you have to do: Verify File Integrity of Silent Hunter 4 (open up STEAM, go into your games, right click on the Silent Hunter 4> then properties then to files and hit the verify button. THEN Verify the File Integrity of Silent Hunter 4 U-Boats Expansion. After the verification finishes it should start to download some files as if updating, Wait to finish and then run the game.
** If this doesn't work YOU HAVE TO UNINSTALL and REINSTALL THE GAME before trying the above procedure** If you have to uninstall, you must do things in this order: Download SH4. Then do the verification on SH4. (it will download more files probably) I can't recall exactly if I did another verification on SH4 again or if I found a manual check for updates there as well, but it took 2 or 3 verifications/check for updates before it found all the updates). Download SH4 UBOAT expansion. Run the verification on the UBOATS expansion. If its good, try launching SH4. You will
NOT need to launch the UBOATS expansion to play it, as it runs from the SH4 application. I don't even know why the UBOATS shows there because it's confusing. You should
NEVER have to launch the Uboats expansion from STEAM.
This is what worked for me. And it's important for some reason to do it in this order, one at a time.
