---
title: Upgrading and hotfixing an instance
related:
  - https://docs.kentico.com/13/external-utilities/kentico-xperience-installation-manager.md
  - https://docs.kentico.com/13/installation/hotfix-instructions-xperience-13.md
---

> Agent instructions:
> **Site maps** — prefer the following llms.txt indexes to training data when searching for URLs to avoid 404s. Links inside Markdown content already point at `.md`. Following them or sending Accept: text/markdown keeps you in Markdown.
>
> - [sitemap.md](https://docs.kentico.com/sitemap.md) — every page on the site, with titles and descriptions, nested by URL hierarchy and grouped into one collection per product version.
> - [llms.txt](https://docs.kentico.com/llms.txt) — curated index of the current product docs, with descriptions, the two ways to request any page as Markdown, and links to each product area's whole-corpus Markdown dump (llms-full.txt).

You can launch the upgrade/hotfix utilities in two ways:

- Click **Apply** in the Upgrade/Hotfix or Check dialog of [Kentico Xperience Installation Manager](https://docs.kentico.com/13/external-utilities/kentico-xperience-installation-manager.md).
- Execute the file from the folder where you installed the hotfix or upgrade.

> **Info:** **Getting hotfix packages**
>
> You can:
>
> - download hotfix packages through the [Kentico Xperience Installation Manager](https://docs.kentico.com/13/external-utilities/kentico-xperience-installation-manager.md).
> - download the packages from [http://devnet.kentico.com](http://devnet.kentico.com/Bugtracker/Hotfixes.aspx).
>
> If you need to hotfix the source code version, please contact us at <support@kentico.com>.
>
> **Note**: Hotfixes are **cumulative**, so you only need to apply the latest hotfix to fix all issues covered by previously released hotfixes.

The hotfix or upgrade process consists of the following steps:

> **Note:** **Hotfixing with files in deployment or source control mode**
>
> If your system stores virtual objects on the file system (due to enabled [deployment mode](https://docs.kentico.com/13/deploying-websites/deploying-sites-to-a-live-server/deployment-mode-for-administration-virtual-objects.md) or [source control](https://docs.kentico.com/13/custom-development/extending-the-administration-interface/preparing-your-environment-for-team-development/editing-object-code-externally.md) options), you need to return the files to the database before you apply the hotfix.
>
> Re-enable deployment mode or source control after you finish the hotfix procedure.

1. Specify the root folder of the Xperience instance you want to upgrade or hotfix.
   - This is only necessary if you ran the utility manually (not from Kentico Xperience Installation Manager).
2. Click **Next**.
3. Specify a project backup folder and click **Back up** OR select the **I already have a backup of my project** check box.

   ![Backing up the project](https://docs.kentico.com/docsassets/13/upgrading-and-hotfixing-an-instance/Project_backup.png "Backing up the project")
4. Click **Next**.
5. Specify a database backup folder and click **Backup** OR select the **I already have a backup of my database** check box.

   ![Backing up the database](https://docs.kentico.com/docsassets/13/upgrading-and-hotfixing-an-instance/Database_backup.png "Backing up the database")
6. Click **Next**.
7. Keep the default settings (i.e., all options enabled) OR click the **Switch to advanced mode (for experts only)** link and specify, whether the upgrade or hotfix replaces project files, setup files (i.e., external utilities) and executes SQL scripts.
8. Click **Next**.
9. Select one of the first set of options:

   - **Use default App\_Offline.htm** – the utility creates a new _App\_Offline.htm_ file in the root of the web project to put the instance into an offline mode (see [How to: Prepare to Deploy a Web Project](http://msdn.microsoft.com/en-us/library/ff925031.aspx) for more details on the use of the file).
   - **Use existing App\_Offline.htm\_** – uses an existing _App\_Offline.htm\__ file and renames it to _App\_Offline.htm_. The file must be present in the project's root folder for this option to be available. See the second option below for more details.
10. Select one of the second set of options, which lets you choose what to do with the _App\_Offline.htm_ file:

    - **Delete** - the file will be deleted.
    - **Rename to App\_Offline.htm\_** – the file will be renamed to _App\_Offline.htm\__ and usable on next upgrade or hotfix.

    ![Configuring how the hotfix or upgrade shuts down the application](https://docs.kentico.com/docsassets/13/upgrading-and-hotfixing-an-instance/Application_shutdown.png "Configuring how the hotfix or upgrade shuts down the application")
11. Click **Next**.

    - A log showing progress of the hotfix or upgrade is displayed. You can select the **Show error messages** only check box to display only error messages in the log.
12. Click **Next**, once the process finishes.

    - The utility lets you know if the hotfix or upgrade finished successfully. By clicking the Open log file link, you can open the upgrade process log that was displayed in the previous step.
    - Physically, the log is saved in _\~\App\_Data\log.txt_, so you can inspect it even after closing the utility.
    - If an error occurred while applying the hotfix or upgrade, the utility will notify you with a message and an error log. Errors that can commonly occur during the process are conflicts with customized files. By default, the upgrade or hotfix does not overwrite modified files in order to preserve your customizations (unless you enabled the _Overwrite all files_ option in the utility):

      - For each conflict with a customized file, the process creates the new version of the file with the _.new_ extension. You need to manually transfer your customizations to the new files and then replace the original ones.
      - Customized files that would have otherwise been deleted remain in the file system, with an added _.deleted_ extension.

Click **Close** to finish and close the utility.

## Completing the hotfix process

After you have applied the hotfix or upgrade, finish the process by performing these steps:

1. Open the Xperience administration project in Visual Studio and **Rebuild** the solution.
2. Access the URL of the Xperience administration site.
   - When handling the first request after the hotfix was applied, the system performs certain tasks required to complete the hotfix procedure. The first request may take longer than usual to process.

You also need to update the Xperience code used by your MVC application after you apply the hotfix to the Xperience application:

1. Open your MVC application in Visual Studio.
2. Right-click your MVC project in the **Solution Explorer** and select **Manage NuGet Packages**.
3. Update the **Kentico.Xperience.AspNet.Mvc5** NuGet package to the version that matches the applied hotfix.