Your software
My Mautic version is: 3.1
My PHP version is: 7.3.19-1~deb10u1
Your problem
My problem is: Getting Invalid backend response.
Error occurred on the server side.
HTTP error 500 when using the image resize option. Error occurs when trying to save the new sized version of the image file.
These errors are showing in the log: [2020-09-15 16:00:53] mautic.CRITICAL: Uncaught PHP Exception Symfony\Component\Debug\Exception\ClassNotFoundException: “Attempted to load class “elFinder” from namespace “Barryvdh\elFinderFlysystemDriver”. Did you forget a “use” statement for another namespace?” at /var/www/html/vendor/barryvdh/elfinder-flysystem-driver/src/Driver.php line 729 {“exception”:"[object] (Symfony\Component\Debug\Exception\ClassNotFoundException(code: 0): Attempted to load class “elFinder” from namespace “Barryvdh\elFinderFlysystemDriver”.\nDid you forget a “use” statement for another namespace? at /var/www/html/vendor/barryvdh/elfinder-flysystem-driver/src/Driver.php:729)"}
Steps I have tried to fix the problem: I have tried to use ‘save as’ as opposed to apply, but same error reported.