When you change the decimal separator from a period (.) to a comma (,) in the regional settings, this breaks the Application Catalog link in Software Center in System Center 2012 Configuration Manager. Additionally, you receive the following error message:
The Website encountered a problem trying to complete your most recent action. The problem could not be resolved automatically. If this problem persists, you can try reloading the web browser and viewing the Application Catalog. Otherwise, contact your helpdesk.
This is a known issue in Microsoft Silverlight.
If your regional language is English, use a period (.) for the decimal separator.