---
title: "TYPO3 Exception 1397836158"
manual: "TYPO3 Exceptions"
version: "main"
permalink: "https://docs.typo3.org/permalink/t3exceptions:typo3-exception-1397836158"
source: "Exceptions/1397836158.rst"
rendered: "2026-09-28T10:25:33+00:00"
---

# TYPO3 Exception 1397836158 {#typo3-exception-1397836158}

> [!NOTE]
> Below, the TYPO3 community may have provided additional information or
> solutions for this exception. However, these may or may not apply to your
> particular case. If you can provide more information, you should come back
> here and add your experience and solution steps to this issue once you have
> resolved it.
>
> General TYPO3 troubleshooting tips can be found in the *Troubleshooting*
> section in the menu. You can also ask questions and receive support in the
> [TYPO3 Questions category on talk.typo3.org](https://talk.typo3.org/c/typo3-questions/).
>
> To add your experience, click "Edit on GitHub" above and follow the
> ["Edit on GitHub" workflow](https://docs.typo3.org/m/typo3/docs-how-to-document/main/en-us/Howto/EditOnGithub.html#docs-contribute-github-method).
> Also check out
> [our tip on Coding Style and reST](https://docs.typo3.org/permalink/t3exceptions:tip-about-rest-coding-style).

## No or invalid extension key "..." given. {#no-or-invalid-extension-key-given}

-   Search for variable `$extensionKey` and replace with the extension key as
    `$_EXTKEY` or string `myExtension`
-   Try not to use `$_EXTKEY` in dynamicConfigFiles or otherwise included
    TCA snippets
-   Check [https://forge.typo3.org/issues/59033](https://forge.typo3.org/issues/59033)

You may have to clear the cache in install tool (See **Important actions**).

[https://docs.typo3.org/typo3cms/InstallationGuide/Upgrade/RemoveTemporaryCacheFiles/Index.html](https://docs.typo3.org/typo3cms/InstallationGuide/Upgrade/RemoveTemporaryCacheFiles/Index.html)