Hey there, it seems a change was just released, enforcing an OAuth Client ID to be provided to connect a new connector:
It doesn’t match the guidelines for the Authentication :
The MCP spec currently requires dynamic client registration (DCR). This means that each time ChatGPT connects, it registers a fresh OAuth client with your authorization server, obtains a unique client_id, and uses that identity during token exchange.
Is it a voluntary change? Should developers adapt?
Having the same issue. Following thread if there is an update. This is preventing me from testing my MCP server 
Having the same issue too. The documentation clearly indicates that dynamic client registration is supported:
I agree that this change goes against guidelines per the MCP spec and has also broken the MCP servers I work with.
That sucks why did they chance stuff every 5 minutes… I hope they fix this real quick or go back to the old format
Looks like it’s working again today. The OAuth Client ID still appears as a required attribute, but adding a new Connector without it is possible.