That class is contained within the class file of GJ and at the top of all the integrations is the below check.

Please ensure you've installed GJ 2.4rc first before installing the integrations. The above prevents the plugin from loading anything if GJs class isn't present. In your case it is, but it's present from an older release. The integrations are not backwards compatible.

You don't need to deinstall anything, just ensure GJ 2.4rc is installed and ensure in plugin management that it is loaded before the integrations. Will be adding an extra check to next release to prevent this from happening. To ensure it is loaded before the integrations simply move its order around, but the first check should've stopped it from loading anyway.

Stable release will feature an additional check for the db class, but still do not see how this is remotely possible unless you failed to install GJ 2.4rc and only upgraded the integrations. The class file, which each integration checks for contains cbgjDBTable at the very top. I could not duplicate your issue regardless however. Please PM backend login credentials and will take a look.