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.

To add your experience, click "Edit on GitHub" above and follow the "Edit on GitHub" workflow. Also check out our tip on Coding Style and reST.

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.