No such warning with Google Chrome. I've had several issues with Firefox previously and don't use it anymore.
I also use AVG Internet Security which evaluates web sites and warns and blocks any suspicious sites. There is a free version as well as an advanced (for pay) version. AVG has no problem with the Hauptwerk Forum.
https://www.avg.com/en-ww/ppc/protection-offer-comparison?dsc=4wf&d=20&ppc=a2&device=c&gclid=EAIaIQobChMIy6r3_va02QIVAylpCh0xBAPIEAAYASAAEgIR6PD_BwE&gclsrc=aw.ds&dclid=CILk3If3tNkCFQWxTwodksIKEA
Rgds,
Ed