Currently i’m upgrading a Neos installation which was still on 3.1.
The upgrade from 3.1 to 3.2 went without issues.
However 3.3 i’m getting a really annoying issue which i can’t seem to backtrace to the root of the problem.
The upgrade itself went fine. Composer, code/doctrine migrations etc.
But now when i open the frontend/backend whatever it fails right away with the Error:
`Cannot set instance of class “Composer\Autoload\ClassLoader” because no matching object configuration was found.
Classes which exist but are not registered are considered to be of scope prototype. However, setInstance() only accepts “session” and “singleton” instances. Check your object configuration and class name spellings
When i go see “Neos.Flow/Configuration/Objects.yaml” the Object is defined right there:
I’ve been trying to clear stuff, removing composer packages, packagestates.php, cache, google-ing.
But no luck so far.
Does anyone maybe have a clue in where to look/what to do?
Thanks in advance