I bought the Leisure Suit Larry pack for Linux but I'm having alot of problems installing. I made the sh installer file executable and I managed to install it but when it's installed it won't start if I click the icon the desktop. I just receive an error message saying like "an error occured at the start of the program". The icon looks quiet weird too with a padlock and an X sign. If I try to enter the Gog folder it says I don't have permission to open it. Could anyone give some advice on what to do?

Did you install it via root (or 'sudo')?
The game should be installed by the user you want to run it with, *not* using sudo.