Copilot Studio connected agent errors: not found, unpublished, auth

Your main agent in Copilot Studio hands work to another agent, and the call fails with a code that starts with ConnectedAgent, such as Connected agent with schema name {AgentSchemaName} not found. A connected agent is a separate, published Copilot Studio agent that your main agent calls, and each of these errors means one link in that setup is missing. Microsoft's error code reference lists five of them, each with its own fix. Most come down to the connected agent itself: where it lives, whether it's published, how users sign in to it, and what it says about itself.

• The main agent's reply, or the test pane, shows a code that starts with ConnectedAgent and names an agent by its schema name.
• It started after the connected agent was created or changed, or after either agent's authentication changed.

This guide covers Copilot Studio agents connected to other Copilot Studio agents in the same environment. Agents from Microsoft Foundry, Microsoft Fabric, the Microsoft 365 Agents SDK or the A2A protocol are connected differently and aren't covered here.

What a connection needs

Microsoft's page on connecting to an existing Copilot Studio agent lists four requirements. Check them first, because two of the five errors, not found and not published, come from one of these missing:

1. The connected agent is in the same environment as the main agent.
2. The connected agent is published.
3. The connected agent allows other agents to connect to it. Learn says any agent in the same environment can connect by default, and that the connected agent's own settings have an option to allow or block this.
4. The maker of the main agent owns the connected agent or has had it shared with them.

Learn adds a fifth point that catches people later: depending on how authentication is set up, the end users of the main agent may also need the connected agent shared with them for it to work at run time.

1. Microsoft Copilot StudioSame environment as the main agent
2. Step 2Connected agent published
3. Step 3Other agents allowed to connect
4. Step 4Matching authentication
5. Step 5Main agent can call it

Which error you have

Microsoft's error code reference lists these five codes for connected agents. In the test pane, Learn says makers see the code with more context. The messages below are Learn's wording; {AgentSchemaName} is the connected agent's schema name.

Fix each error

ConnectedAgentBotNotFound

Learn's checks, in order:

1. Make sure the connected agent is in the same environment as the main agent. An agent in another environment can't be connected this way.
2. Check that the schema name in the main agent's configuration is spelled correctly.
3. Check that you have access to the connected agent: you own it or it's shared with you.
4. If you only just created the connected agent, wait a few minutes and try again.

To take a connected agent off the main agent, Learn's overview of adding other agents describes disconnecting it from the main agent's list of agents.

ConnectedAgentBotNotPublished

The main agent can only call a connected agent that has been published.

1. Open the connected agent in Copilot Studio.
2. Publish it.
3. Go back to the main agent and test again.

The same rule applies to every later change. Learn says the main agent uses only the latest published version of a connected agent, so an edit you saved but didn't publish isn't what the main agent runs.

ConnectedAgentAuthMismatch

The main agent and the connected agent have authentication settings that don't fit together. Open both agents and compare them in the agent's settings, under security and then authentication. Learn describes three options there: no authentication, authentication with Microsoft, and manual authentication.

Learn's compatibility rules:

• If the connected agent has no authentication, the main agent can use any authentication.
• If the connected agent requires authentication, the main agent must use the same method, for example both using authentication with Microsoft.
• Manual authentication with Generic OAuth 2 on the main agent doesn't work with a connected agent that requires authentication, unless both agents use the same manual configuration (same provider and settings).

Learn's authentication page adds that authentication changes take effect only after you publish. So after you change either agent, publish it, then test the main agent again.

ConnectedAgentChainingNotSupported

Connections go one level deep. A main agent can call connected agents, but those connected agents can't have connected agents of their own. Learn also lists the reverse in its known limitations: an agent that already has connected agents can't itself be connected to a second main agent.

Learn's fix is to flatten the design:

1. Review how the agents call each other, and remove the extra level.
2. Move what the deeper agent does into the main agent or into a first-level connected agent.
3. Consider topics or actions instead of another connected agent.

ConnectedAgentGptComponentNotFound

The main agent decides when to call a connected agent from what that agent says about itself. If the description or instructions are missing, there's nothing to decide on.

1. Open the connected agent and go to its overview.
2. Give it a clear description and clear instructions.
3. Publish the connected agent.
4. Return to the main agent and test again.

When you connect an agent, the main agent keeps its own copy of the description, which you can edit. Learn says later changes to the connected agent's own description don't sync to the main agent; update the local copy by hand when it changes.

It works for you but not for your users

If you can use the main agent but other people get errors when it hands over, look at sharing and sign-in:

• Learn says that, depending on your authentication setup, you might need to share the connected agent with the main agent's end users so it works for them at run time.
• Check both agents' authentication again (see ConnectedAgentAuthMismatch) and that both are published after the last change.
• In Teams, our guide to a Copilot Studio agent not working in Teams covers channel-specific causes, including sharing connected agents.

AIPluginOperationNotFound after an import

Learn's error code reference describes AIPluginOperationNotFound as an error when trying to reach a connected agent. Users see "Sorry, the bot can't talk for a while. It's something the bot's owner needs to address." Learn's fix is to republish the agent; the error can happen when an agent is published through an import or a solution deployment.

Related guides

For what connected agents are and where they fit, see what is Copilot Studio and which Microsoft agent tool to use. If the error instead names a flow, our guide to Copilot Studio FlowActionBadRequest covers refreshing and republishing flows.

The steps in this guide follow Microsoft's documentation as of 28 October 2026; we haven't run them in a tenant.

Sources

• Resolve Microsoft Copilot Studio agent error codes — Microsoft Learn
• Connect to an existing Copilot Studio agent — Microsoft Learn
• Add other agents overview: known limitations and managing connected agents — Microsoft Learn
• Configure user authentication in Copilot Studio — Microsoft Learn
• Share agents with other users — Microsoft Learn