Unable to Authenticate when installing Lightroom 6 on new hard drive.

This week I installed LR 6 Classic on a new HD. I have done this before and it is running fine on my previous HD. But now suddenly the athentication fails (e.g. it gets into a loop) and LR6 doesn't start anymore.
I have contacted support and they bluntly say to f0ck off because LR6 is not supported anymore.
But I don't need support on LR6, that is working fine. I need them to restore my authentication feature.
But NO I need to buy a subscription which I won't because I do not use it often and LR6 which I payed for the total package is working good enough.
THIS IS PURE BLACK MAIL.
I bougt a car which is working fine but now I moved to another home the manufacture disabled my car forcing me to buy another on SUPSCRIPTION BASE!!!

I am so angry. Never would have expected this from an respected company. When I buy another camera and need driver support on LR I would have considered a new version of LR but now... NO, NEVER!

WHO knows a good solution?