Dotfuscator Professional requires activation before you are able to use it. The first time you install Dotfuscator you will be prompted for your license key. However, if you skip the activation step or there is an activation error, the install will complete and activation can be completed by running the Dotfuscator Config Editor.
If you purchased a subscription license (as opposed to a perpetual license) of Dotfuscator, then after activation Dotfuscator will attempt to download your registration and subscription information from PreEmptive's servers. If your subscription has expired, you will be prompted to renew your subscription.
Dotfuscator will run in reduced functionality mode if your subscription has expired and you have not renewed it. Dotfuscator's status bar will alert you if your subscription needs attention, and give you a link to the appropriate resource. Once you have updated your subscription, re-launch Dotfuscator and it will download the updated information from PreEmptive's servers and once again operate in full functionality mode.