---
title: "TYPO3 Exception 1294587486"
manual: "TYPO3 Exceptions"
version: "main"
permalink: "https://docs.typo3.org/permalink/t3exceptions:typo3-exception-1294587486"
source: "Exceptions/1294587486.rst"
rendered: "2026-10-30T07:15:30+00:00"
---

# TYPO3 Exception 1294587486 {#typo3-exception-1294587486}

> [!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).

TYPO3 9.5.23 and the extension phpmyadmin 5.6.4 result in error message

```
Session already started by session_start(). Make sure no installed extension is starting a session in its :file:`ext_localconf.php` or :file:`ext_tables.php`.

```

when logging in to **Admin Tools** (Maintenance, Settings, Update,
Environment) in Backend.

Solution: uninstall phpmyadmin, delete cookies, re-login