Array ( [Warning] => [Error] => Unsupported post request. Object with ID ‘892581

does not show closed groups or open that I adminstro, only pages.

Same here
Started after plugin update last night
No change after the second update this morning
No comments imported either since about 14:00 hours ETS yeasteday
Plugin has been working for us for years now without touching the settings
Group has been open group since the start

Full error
[2018-04-05 08:00:34] – [Error] [Facebook – fb] – -=ERROR=- Array ( [Warning] => [Error] => Unsupported post request. Object with ID ‘64012343*****’ does not exist, cannot be loaded due to missing permissions, or does not support this operation. Please read the Graph API documentation at https://developers.facebook.com/docs/graph-api | Are you posting to a secret or closed group? Please see: https://gd.is/fbe2 )

I hope you can solve this problem as soon as possible.

Facebook disabled Groups API. Autoposting to Groups is no longer possible.

Here is more info:
https://www.nextscripts.com/news/2018/04/facebook-problems-and-changes/

several people I know bought the plugin because of posting in groups, please fix the new way as soon as possible, good work.

+1 Posting to closed groups is MUST HAVE feature. This is important!