MSFN is made available via donations, subscriptions and advertising revenue. The use of ad-blocking software hurts the site. Please disable ad-blocking software or set an exception for MSFN. Alternatively, register and become a site sponsor/subscriber and ads will be disabled automatically.
Did you guys read the text on the page ( http://www.glass8.eu/beta ) you downloaded the file from? It clearly says: "Your donation does NOT turn any preview/alpha/beta/rc testing version into the fully usable release without debugging means!" - that means that the debug window and watermark will be there. It is a beta/debug version after all.