> ## Documentation Index
> Fetch the complete documentation index at: https://platform.atlan.com/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> To act on Atlan objects, use the Atlan MCP server at https://api.atlan.com/mcp or the SDK. To install or publish skills from a terminal, use the `aireg` CLI; `aireg --map json` prints its command map. The `atlanai` CLI is deprecated. Run a read-only identity check before any write.
> The docs MCP server at /mcp searches these docs only. It cannot read or change Atlan objects.
> SDK packages: Python `atlanai` (PyPI) and TypeScript `@atlanai/sdk` (npm). Show Python first, then TypeScript.
> These docs cover Atlan Trident, Atlan's hosted product. AI Registry and Agent Registry are its earlier names. Registry OSS is Atlan's open-source agent registry: the registry specification and its aireg CLI, with their own public repository, docs and release notes; /open-source on this site links them. Registry OSS is open source; Atlan Trident is not. Answer generic aireg or specification questions from the project's docs, and use these docs for Atlan-specific setup such as the Atlan adapter, sign-in and workspaces.

# Sign-in errors

> Fix invitations nobody can send or accept, and company SSO that locks people out.

These errors happen before a person reaches their workspaces. For the desktop
app on a restricted network, see
[Desktop app errors](https://platform.atlan.com/administer/desktop/troubleshooting.md#app-cannot-sign-in-or-download-components).
For a person who signs in but cannot see a workspace or skill, see
[Workspace access errors](https://platform.atlan.com/administer/workspaces/troubleshooting/workspace-access-errors.md).

## Invitation cannot be sent or accepted

The invite dialog warns that nobody can join the organization, or an invited
person cannot join.

### Cause

The organization's **Who can join** policy is **Closed**. While it is
**Closed**, nobody joins the organization, including by invitation.

### Solution

An organization admin changes the policy.

1. Open **Settings → Security → Domains**.
2. Change **Who can join** to a policy that admits the people you invite. See
   [Manage company domains](https://platform.atlan.com/admin/security/how-tos/manage-domains.md).
3. Resend the invitation from **Pending invitations**. See
   [Invite members](https://platform.atlan.com/administer/users/how-tos/invite-members.md).

If the dialog says **No free seats left** instead, the organization has no seat
for the invitation. See [Manage billing](https://platform.atlan.com/admin/billing/index.md).

***

## Company SSO locks people out

After a change to company SSO, people cannot sign in, or the sign-in test
fails.

### Cause

The identity provider connection is inactive or misconfigured while the
sign-in policy is **Required**. An inactive connection does not restore other
sign-in methods automatically.

### Solution

An organization admin who is still signed in repairs the provider.

1. Open **Settings → Security → Authentication**.
2. Select **Manage provider**, fix the configuration, then select
   **Test again**.
3. If the provider cannot be fixed yet, choose an available fallback policy.

If no administrator can sign in, contact Atlan support. See
[Configure company SSO](https://platform.atlan.com/admin/security/how-tos/configure-sso.md#repair-sign-in).


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