ERROR: FileRead(): SSL error on fd

I'm running conserver-8.2.4 on a 64bit Linux server, with a large
number of servers with
console sessions being managed by conserver.  I've recently noticed
that every time someone logs out from a console session, the following
error is generated:

ERROR: FileRead(): SSL error on fd 4

The file descriptor changes periodically, but the rest of the error is
the same every time.  Here's a snippet from the log showing the the
full order of events:

[Wed Aug 14 20:23:32 2019] conserver (5095): ERROR: FileRead(): SSL
error on fd 4
[Wed Aug 14 20:23:32 2019] conserver (5095): [c046.sjc005.ix] logout
root@localhost
[Wed Aug 14 20:23:35 2019] conserver (5095): ERROR: FileRead(): SSL
error on fd 4
[Wed Aug 14 20:23:35 2019] conserver (5095): [c045.sjc005.ix] logout
root@localhost
[Wed Aug 14 20:23:41 2019] conserver (5092): ERROR: FileRead(): SSL
error on fd 105
[Wed Aug 14 20:23:41 2019] conserver (5092): [c043.sjc005.ix] logout
root@localhost
[Wed Aug 14 20:23:44 2019] conserver (5092): ERROR: FileRead(): SSL
error on fd 18
[Wed Aug 14 20:23:44 2019] conserver (5092): [c042.sjc005.ix] logout
root@localhost
[Wed Aug 14 20:23:47 2019] conserver (5092): ERROR: FileRead(): SSL
error on fd 18
[Wed Aug 14 20:23:47 2019] conserver (5092): [c041.sjc005.ix] logout
root@localhost
[Wed Aug 14 20:24:11 2019] conserver (4586): ERROR: FileRead(): SSL
error on fd 99
[Wed Aug 14 20:24:11 2019] conserver (4586): [c050.gru001.ix] logout
root@localhost
[Wed Aug 14 20:24:17 2019] conserver (4547): ERROR: FileRead(): SSL
error on fd 93
[Wed Aug 14 20:24:17 2019] conserver (4547): [c024.ewr002.ix] logout
root@localhost

Any ideas what is going wrong here?  It doesn't seem like the errors
are causing any obvious problems.

thanks