Express Entity Attribute Not Found Error

I am having an issue with Express entity attributes. I am able to add new Express objects just fine, but when I go to select the "Attributes" panel for editing these, I am thrown an error:

Doctrine \ ORM \ EntityNotFoundException
Entity of type 'Concrete\Core\Entity\Package' for IDs pkgID(5) was not found
class EntityNotFoundException extends ORMException
     * Static constructor.
     * @param string   $className
     * @param string[] $id
     * @return self
    public static function fromClassNameAndIdentifier($className, array $id)
        $ids = array();

This was happening in 8.3.2, but then I manually upgraded 8.5.2, but this didn't fix the issue. I am running PHP version 7.0.33.

I'm perplexed. What might be causing this?

View Replies: View Best Answer
PineCreativeLabs replied on at Permalink Reply
UPDATE: I just got the same issue with trying to set up Page attributes, so this seems to have to do with attributes overall.

Can someone shed some light on this issue? Is something corrupted in the database?
PineCreativeLabs replied on at Permalink Best Answer Reply
FIXED IT! The culprit was an addon that I uninstalled a while back, which caused the pkgID to no longer exist in the DB. I re-installed the package, then updated the pkgID so it used the previous ID (pkgID(5)). Then, the package itself had some deprecated code, which broke the attributes editing. After fixing the deprecated code, everything now works.
ConcreteOwl replied on at Permalink Reply
Well done for figuring it out.
I have marked your post as Best Answer.