TYPO3 Core

How to reproduce:

Install TYPO3 13.1 and main-dev of blog_example: https://github.com/TYPO3-Documentation/blog_example

Go in the Backend module and hit "Generate data"

try to open one of the generated blogs.

There is a warning:

PHP Warning
Core: Error handler (BE): PHP Warning: Array to string conversion in /var/www/html/vendor/typo3/cms-backend/Classes/Utility/BackendUtility.php line 1534

This is due to the fact that $row does not only contain scalar values but seems to also contain arrays that cannot be casted to a string.

This was caused by trying to renderForeignRecordHeader in InlineRecordContainer:324 and seems to only happen when the record to be displayed in irre has ctrl->label_alt set and label_alt is pointing to a field which is a select box.