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The SAML application that was created during [Single sign-on](index.md) setup for [Azure](https://docs.microsoft.com/en-us/azure/active-directory/manage-apps/view-applications-portal) now needs to be set up for SCIM.
You can then test the connection by clicking on **Test Connection**. If the connection is successful, be sure to save your configuration before moving on. See below for [troubleshooting](#troubleshooting).
Follow [Azure documentation to configure the attribute mapping](https://docs.microsoft.com/en-us/azure/active-directory/app-provisioning/customize-application-attributes).
For guidance, you can view [an example configuration in the troubleshooting reference](../../../administration/troubleshooting/group_saml_scim.md#azure-active-directory).
Once synchronized, changing the field mapped to `id` and `externalId` may cause a number of errors. These include provisioning errors, duplicate users, and may prevent existing users from accessing the GitLab group.
bar and select **Classic UI**. Otherwise, you may not see the buttons described
in the following steps:
1. In the **Application** tab, click **Add Application**.
1. Search for **GitLab**, find and click on the 'GitLab' application.
1. On the GitLab application overview page, click **Add**.
1. Under **Application Visibility** select both check boxes. Currently the GitLab application does not support SAML authentication so the icon should not be shown to users.
1. Click **Done** to finish adding the application.
1. In the **Provisioning** tab, click **Configure API integration**.
1. Select **Enable API integration**.
- For **Base URL** enter the URL obtained from the GitLab SCIM configuration page
- For **API Token** enter the SCIM token obtained from the GitLab SCIM configuration page
1. Click 'Test API Credentials' to verify configuration.
### How come I can't add a user after I removed them?
As outlined in the [Blocking access section](#blocking-access), when you remove a user, they are removed from the group. However, their account is not deleted.
When the user is added back to the SCIM app, GitLab cannot create a new user because the user already exists.
Solution: Have a user sign in directly to GitLab, then [manually link](#user-access-and-linking-setup) their account.
Ensure that the user has been added to the SCIM app.
If you receive "User is not linked to a SAML account", then most likely the user already exists in GitLab. Have the user follow the [User access and linking setup](#user-access-and-linking-setup) instructions.
The **Identity** (`extern_uid`) value stored by GitLab is updated by SCIM whenever `id` or `externalId` changes. Users cannot sign in unless the GitLab Identity (`extern_uid`) value matches the `NameId` sent by SAML.
It is important that this SCIM `id` and SCIM `externalId` are configured to the same value as the SAML `NameId`. SAML responses can be traced using [debugging tools](index.md#saml-debugging-tools), and any errors can be checked against our [SAML troubleshooting docs](index.md#troubleshooting).
A possible alternative is to use the [SCIM API](../../../api/scim.md#get-a-list-of-scim-provisioned-users) to manually retrieve the `externalId` we have stored for users, also called the `external_uid` or `NameId`.
To see how the `external_uid` compares to the value returned as the SAML NameId, you can have the user use a [SAML Tracer](index.md#saml-debugging-tools).
If the GitLab `externalId` doesn't match the SAML NameId, it needs to be updated in order for the user to sign in. Ideally your identity provider is configured to do such an update, but in some cases it may be unable to do so, such as when looking up a user fails due to an ID change.
- You can have users unlink and relink themselves, based on the ["SAML authentication failed: User has already been taken"](index.md#message-saml-authentication-failed-user-has-already-been-taken) section.
- It may be possible to use the [SCIM API](../../../api/scim.md#update-a-single-scim-provisioned-user) to manually correct the `externalId` stored for users to match the SAML `NameId`.
It is important not to update these to incorrect values, since this causes users to be unable to sign in. It is also important not to assign a value to the wrong user, as this causes users to get signed into the wrong account.
Individual users can follow the instructions in the ["SAML authentication failed: User has already been taken"](index.md#i-need-to-change-my-saml-app) section.
Alternatively, users can be removed from the SCIM app which de-links all removed users. Sync can then be turned on for the new SCIM app to [link existing users](#user-access-and-linking-setup).
| SAML and SCIM identity mismatch. | First [verify that the user's SAML NameId matches the SCIM externalId](#how-do-i-verify-users-saml-nameid-matches-the-scim-externalid) and then [update or fix the mismatched SCIM externalId and SAML NameId](#update-or-fix-mismatched-scim-externalid-and-saml-nameid). |
| SCIM identity mismatch between GitLab and the Identify Provider SCIM app. | You can confirm whether you're hitting the error because of your SCIM identity mismatch between your SCIM app and GitLab.com by using [SCIM API](../../../api/scim.md#update-a-single-scim-provisioned-user) which shows up in the `id` key and compares it with the user `externalId` in the SCIM app. You can use the same [SCIM API](../../../api/scim.md#update-a-single-scim-provisioned-user) to update the SCIM `id` for the user on GitLab.com. |
When testing the connection, you may encounter an error: **You appear to have entered invalid credentials. Please confirm you are using the correct information for an administrative account**. If `Tenant URL` and `secret token` are correct, check whether your group path contains characters that may be considered invalid JSON primitives (such as `.`). Removing such characters from the group path typically resolves the error.