The only time I have seen this is when a post is deleted before it is approved/disapproved and the way I found to fix it, there may be other ways, was to actually edit the database - but I would only recommend doing that if you are sure of what you are doing and you have a backup.
Remember: You only know what you know and - you don't know what you don't know!
My CDB Contributions | How to install an extension
I will not be accepting translations for any of my extensions in Github - please post any translations in the appropriate topic.
No support requests via PM or email as they will be ignored