Sudden Sharepress error posting in facebook

Last WP version, up-to-date plugins. I use sharepress plugin to automatically post new entries to some facebook pages.

Suddenly I started to get this error I receive by email and it is in log flie

[Sat Jan 31 07:51:58 2015] [warn] [client: local IP ] mod_fcgid: stderr: SharePress Error: Problem with the SSL CA cert (path? access rights?); while sending --post-name-- --url-post for post 1103, referer: wp-admin/post.php?post=1103&action=edit

No new posts are added to fb.

SSL is not used in this virtual server. Plugin's author says it could be a facebook problem. I don't know where is the origin of the problem.

Log lines before that one are a dozen, exactly the same (time also) as this one

[Sat Jan 31 07:51:34 2015] [warn] [client server's IP ] mod_fcgid: stderr: Problem with the SSL CA cert (path? access rights?)