AVG Ultimate (multi device) activation issues

I can’t activate my AVG Ultimate (multi device) with activation code. After installation of the app according to instructions from “https://www.avg.com/activation”, app keeps showing me error that “This code is for a different application”. I am sure I chose correct application from AVG website. I have tried also more of various available options for AVG Ultimate activation, although in vain.
Please, advise, how I could get my AVG Ultimate (multi device) subscription activated.