@pitaj This seems to be a new requirement, so if that is truly the case, then our Facebook SSO plugin is not compatible with the latest Facebook changes.
Thanks for reporting
Looks like that post doesn't have a valid uid, if you know its poster's uid then you can fix it by.
hset post:10825 uid <theiruid>
If they are deleted then just set their uid to 0 with
hset post:10825 uid 0
I guess thats something the importer should do.