---
title: "TYPO3 Exception 1439555561"
manual: "TYPO3 Exceptions"
version: "main"
permalink: "https://docs.typo3.org/permalink/t3exceptions:typo3-exception-1439555561"
source: "Exceptions/1439555561.rst"
modified: "2026-09-16T07:39:08+00:00"
---

# TYPO3 Exception 1439555561

> [!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).

## The composer.json found for extension "..." is invalid!

A `composer.json` file has a syntax error. Use the command line
`composer.phar validate` to get details about this error and the line
number which causes this error.

This error can also occur if the `composer.json` file is not accessible.

Alternatively, use a JSON online validator and copy-paste the contents of your
`composer.json`. Then you will see the exact syntax error in this JSON
file. E.g. [here](https://jsonformatter.curiousconcept.com/).