If configuration of exclude_directories is not written an exception occurs

[mgerdes-atl]

If the configuration is not written (we had an TYPO3 upgrade project 11 -> 12)

Uncaught TYPO3 Exception explode(): Argument #2 ($string) must be of type string, null given
thrown in file plan2net/webp/Classes/EventListener/AfterFileProcessing.php
in line 160

Easy patch would be to go to '' on null as shown in exclude_directories_not_configured.TXT patchfile

[BrandSven]

+1, stumbled into the same issue when upgrading 11 -> 12

It's easily fixed (log in to the standalone install tool, go to settings -> Extension configuration -> webp and just save once using the button on the bottom of the page), though.