Same problem here, same Wordfence version (6.1.12) and Wordpress 4.5.3. Right in the middle of the additional files scan:
[Jul 27 01:26:52] Scanned contents of 495 additional files at 20.63 per second
[Jul 27 01:26:53] Notice: Undefined index: coreUnknown in ***path redacted***/wp-content/plugins/wordfence/lib/wordfenceHash.php on line 141
[Jul 27 01:26:53] Scanned contents of 548 additional files at 21.91 per second
Additionally I have this notice at the very end:
[Jul 27 01:28:26] Notice: An unexpected error occurred. Something may be wrong with WordPress.org or this server’s configuration. If you continue to have problems, please try the support forums. (WordPress c
And yes, that really is cut off at the c
like that, there is nothing after that. So I'm not quite sure what this "unexpected error" actually is.