I don't seem to be able to get fortress to update or createe the authorized_keys2 file. If the file already contains the user's public key, authentication works.  But if a new user supplies their public key for the first time and file does not exist and authenticates using their domain password I get errors like this in the fortress log:

Server Fatal error: recv from socket failed: No such file or directory

And like this in the event log:

Unable to stat() authorized keys file  [path to file]

It also does not work if the file exists and is empty.

I suspect I am missing a permission, but it's not clear which. Or is there something else wrong?

The fortress version is: Version:  5.0 Build 9 Revision 2031

Thanks.