v0 project access error "You do not have access to username/project" and sandbox failures

Problem

I’m experiencing authentication and sandbox connectivity issues with my v0 project.

Current Behavior

When opening the v0 chat, I see the error:

"You do not have access to username/project"

The chat agent reports technical difficulties:

"I apologize, but I’m currently experiencing technical difficulties accessing the sandbox environment. The system is returning “Failed to get agent sandbox” errors for all file operations."

I am unable to create a new branch or start a new chat for that project.

What I've Tried

Signed out and signed back in.
Cleared browser cookies.
Cleared Vercel tokens.
Attempted to prompt the chat to resolve the issue.

Expected Behavior

I expect to be able to preview my project, access the sandbox environment, and create new branches or chats without permission errors.

Did you know there's another category dedicated to #v0 topics? A human should be here soon to help, but the answer may already be available even faster in one of these other posts.

Our docs are a great place to start.

https://vercel.com/docs/v0

We also have a walkthrough to help guide your workflow.

https://community.vercel.com/t/become-a-v0-expert/5981

And these recordings can give you a look at v0 features and strategies in action shown by our Community:

https://community.vercel.com/tags/c/events/42/v0

Resolved in DM, this happened because of the project was in a private git repo without access