Hi @anstro thanks for getting in touch and sorry to hear you’re having this problem. We have seen this problem in the past caused by a setting in the Brave browser which is switched on by default causing this error and stopping you from setting up Site Kit.
If you are using the Brave browser then you will need to switch this setting off to complete Site Kit setup. This will also stop you connecting any of the modules within Site Kit if this setting is switched back on.
Please could you confirm if this is the cause and if not then I will be happy to look further into this for you.
OK, problem solved. Thanks for your help.
You are welcome and glad to be able to assist. Good luck with your Website and do let us know if there is anything else we can help with.