After the game is updated it runs checks on the integrity of the game and the installation. If problems are detected then it will go in to 'Demo' mode.
These problems can only occur if you have a a corrupted or invalid installation, or if you originally had a cracked/counterfeit version installed and it was not entirely un-installed before a full purchased version was installed.
If you're getting this error and you have now purchased SR2020, do a full uninstall then reinstall, then install the Update. In some cases under Windows Vista, a cracked version may leave settings in the registry that will need to be removed manually.
If you continue to have problems, please send an email to firstname.lastname@example.org
with where you bought the game and your CD Key / Activation code, and we'll help you out.