GaRebel, I don't have the gamestop version but one thing to try is to open SH5 folder in explorer.

Then open the Support folder.

You should see a folder called Game Updater

open that and double click GU.exe

Follow the on-screen prompts to check for update and update your game. It may seem to hang during the download or installation. I think after the update is downloaded a new window pops up to install the update.

I always run the program again after it's done to make sure the GU.exe recognizes that my game is up to date.

Good luck! And make sure to check out the FAQs across the site as well as the links in THEBERBSTER's sig. A little homework helps people not have to answer the same questions over and over.