Developer, please check

Dear VRChat developer, There seems to be a problem with SDK, so please check whether it is a problem with SDK or Unity, and if the problem is found, please solve it quickly.

You will have to provide more information on what the problem is if you want someone to help you with it unfortunately

Additionally, this is the user side of the vrchat community. It’s for users to help each other out regarding making content. And as far as I’m aware, following the guide Setting up the SDK works just fine.

So without more information, we can’t really help.

If it’s something that’s a security risk or whatever, you can report it through this page instead:
https://help.vrchat.com/hc/en-us

If you want to report a bug then you can use this page:

If it’s a suggestion you want to make use this page: