Approving topics in moderation is not working
This is not a proper way to find the problem's cause.
Follow the standard WP procedure for debug. Part of if was posted above by Robert. Enable WP Debug.log also.
This issue is already fixed in next release please wait for the next version release.
I'm not sure what you mean by "not proper" way. This is obviously a bug in the plugin, it seems like the developer simply copy pasted his code above it:
So it would take some times for the admin to act on this simple bug.
Sorry, i didn't realized it was a bug.