# Troubleshooting

> This page provides a list of the most common installation issues and the corresponding fixes.

## Action Center installation troubleshooting

This page provides a list of the most common installation issues and the corresponding fixes.

If the issue you're facing is not in the list, contact [our support team](https://customerportal.uipath.com/support/add-case).

### Installation successful, but you cannot access Action Center

**Description**: Installation completed successfully, but you cannot access Action Center.

#### Remedy
1. Install the ASP.NET Hosting Bundle:
* minimum version 3.1.x, available [here](https://dotnet.microsoft.com/download/dotnet-core/3.1) or,
* version 5.0.x, available [here](https://dotnet.microsoft.com/download/dotnet/5.0).

### Cannot access Action Center using the load balancer URL

**Description**: You cannot access Action Center using the load balancer URL.

#### Remedy
1. For each Action Center node specify their corresponding **hostname** and **port**in the **Action Center IIS Settings** screen.
2. Update the common load balancer URL with the Action Center URL (for example, https://action-center.domain.com) in the **Action Center UiPath Identity Settings** screen.

### Unregistered Client Error

**Description**: When accessing Action Center using the load balancer URL, Identity Server responds with the `Unregistered Client Error` message.

#### Remedy
1. Update the Subject Alternative Name (SAN) to include all node and load balancer host names:
* use a wildcard pattern such as `DNS Name = *.domain.com`, or
* specify each hostname in the SAN

### Image or PDF files not loading in forms.

**Description**: Image or PDF files are not loading inside Form Actions.

#### Remedy
1. Verify the `<appSettings>` property in the `UiPath.Orchestrator.dll.config` file and make sure that:
* the value of the `AcceptedRootUrls` key does not include space characters,
* the **port** value for Action Center URL is specified only when it is different than **80** or **443** (default ports).

**Additional information**: Find more information [here](https://docs.uipath.com/action-center/standalone/2024.10/user-guide/installation#orchestrator-settings-to-accept-storage-bucket-requests-from-action-center).

### Action Center not loading, because of 404 response code

**Description**: Action Center does not load because `.json` and `.woff2` MIME types used by the Action Center WebApp provide a 404 response code

#### Remedy
1. For each Action Center node, add the `.json` and `.woff2` MIME types in **IIS** > **Mime types** > **Add**:
* **File name extension**: `.json`, **MIME type**: `application/json`.
* **File name extension**: `.woff2`, **MIME type**: `application/font-woff2`.

### PaaS installation using Terraform

**Description** This issue occurs for PaaS installations run through Terraform. Installation completed successfully, however, Action Center does not load and displays the following message: "You do not have permissions to view this directory or page".

**Remedy**: Add `index.html` in the **Default documents** section of your cloud provider:
1. Go to your **App Services** in Azure.
2. Navigate to **Settings**.
3. Open the **Configuration** page.
4. Switch to the **Default documents** tab.
5. Click **+ New Document**.
6. Add `index.html`.

### Upgrading successful, cannot access Action Center via Load Balancer URL

**Description**: Upgrading to higher versions of Action Center was successful, but cannot access Action Center via the `load balancer URL`. This issue applies if the `Host URL` is different than the `load balancer URL`.

This issue also applies if the DNS name is different than the machine name.

#### Remedy
1. In the `ActionCenter/Actions/environments/env.json` key, manually update the values for `businessUserPortalProxyServiceUrl` and `postLogoutRedirectUri` to the correct `load balancer URL`.
2. In the `ActionCenter/Processes/environments/env.json` key, manually update the values for `businessUserPortalProxyServiceUrl` and `postLogoutRedirectUri` to the correct `load balancer URL`.

### Upgrade successful, cannot access Action Center

**Description**: After upgrading Action Center from 2021.4 to 2022.10, the access is blocked by the CORS policy.
* **Event log** error - *IdentityServer4.Hosting.CorsPolicyProvider CorsPolicyService did not allow origin.*
* **Console** error - *Access to XMLHttpRequest at '<changed_action_center_url>/actioncenterservice/feature/features/ActionApp' from origin '<action_center_url>' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: The 'Access-Control-Allow-Origin' header has a value '<action_center_url>' that is not equal to the supplied origin.*

**Cause**: The **Action Center URL** changed its value inside the Registry after upgrading to a higher version.

#### Remedy
1. Update the **Action Center URL** with the correct value for **Actions**:
   * Go to the **ActionCenter/Actions/environments/env.json** file path.
   * Change the value for **action_center_url** inside the **"businessUserPortalProxyServiceUrl"** key.

     The format for the **"businessUserPortalProxyServiceUrl"** key is `<actioncenter url>/actioncenterservice`.
   * Change the value for **action_center_url** inside the **"postLogoutRedirectUri"** key.

     The format for the **postLogoutRedirectUri** is `<action_center_url>/actions`.
2. Update the **Action Center URL** with the correct value for **Processes**:
   * Go to the **ActionCenter/Processes/environments/env.json** file path.
   * Change the value for **action_center_url** inside the **"businessUserPortalProxyServiceUrl"** key.

     The format for the **"businessUserPortalProxyServiceUrl"** key is `<actioncenter url>/actioncenterservice`.
   * Change the value for **action_center_url** inside the **postLogoutRedirectUri** key.

     The format for the **postLogoutRedirectUri** is `<action_center_url>/processes`.

### Access to XMLHttpRequest has been blocked by CORS policy

**Description**: You're using Orchestrator storage buckets, and when you try to access document validation actions, the following errors are thrown:
* *Could not connect to the server*
* *An error occurred while retrieving the DOM (Document Object Model)*

**Cause**: The `<cors>` section in Orchestrator's `web.config` file overrides the **Action Center URL** that you input in the `"AcceptedRootUrls"` key from the `UiPath.Orchestrator.dll.config` file.

**Remedy**: Perform the following steps to fix the issue:
1. Open the `web.config` file from Orchestrator.
2. Find a section that contains `<cors>`.
3. If this section exists, then add the **Action Center URL** in this section, as well.