[ZendTo] 500 server error on successful AD authentication

[Bailey Coole]

We're running 6.05-4 on CentOS 8.

If an AD user successfully authenticates, they get a 500-server error.
If an AD user inputs an incorrect password, they are warned that "The username or password was incorrect" (as expected).
If a local (i.e., admin) user authenticates, everything 'works' properly.

I don't *think* this is an issue with the ldap/AD config as ldapsearch with the same inputs returns all the expected users and the same settings (different bind account) are in use elsewhere in our infrastructure.
Nothing showing in the apache logs, but there is a Fatal error in the php log:

[11-Dec-2020 17:45:36 Australia/Perth] PHP Warning:  Attempt to read property "value" on null in /var/zendto/templates_c/9da848d4b67ceaa147b62c8524dedce691bc7ce2_0.file.header.tpl.cache.php on line 424
[11-Dec-2020 17:45:42 Australia/Perth] PHP Fatal error:  Uncaught TypeError: Cannot access offset of type string on string in /opt/zendto/lib/NSSADAuthenticator.php:658
Stack trace:
#0 /opt/zendto/lib/NSSADAuthenticator.php(485): NSSADAuthenticator->Tryauthenticate()
#1 /opt/zendto/lib/NSSMultiAuthenticator.php(154): NSSADAuthenticator->authenticate()
#2 /opt/zendto/lib/NSSDropbox.php(2332): NSSMultiAuthenticator->authenticate()
#3 /opt/zendto/lib/NSSDropbox.php(620): NSSDropbox->userFromAuthentication()
#4 /opt/zendto/www/index.php(35): NSSDropbox->__construct()
#5 {main}
  thrown in /opt/zendto/lib/NSSADAuthenticator.php on line 658

Any ideas on what could be causing this behaviour?

Thank you


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://jul.es/pipermail/zendto/attachments/20201211/16963c2e/attachment.html>