[horde] "User {username} is not authorized for Mail" after a routine update

[Rob Dueckman]

I had to update my server OS, but maintained the same version PHP
(7.4.28) in order to be compatible with Horde.

After the upgrade, it appears that session data no longer contains the
imp entry for the logged in user.   I haven't been able to find
anything in the php logs, apache logs, or the horde logs that would
point to where the issue might be.

Authenticated applications listed in the session: horde, "ingo,
kronolith, turba, nag, mnemo, trean, ansel, timeobjects, content"
Authenticated applications listed in the session (after mail login
below): "horde, ingo, kronolith, turba, nag, mnemo, trean, ansel,
timeobjects, content, imp"

If I log in, then visit the imp landing page (Login to Mail), I am
asked to log into imp.  Using the same user credentials as the main
Horde login gives the following error:

A fatal error has occurred
IMP is marked as authenticated, but no credentials can be found in the
session.
in /usr/share/pear/Horde/Registry.php:1679
1. Horde_Registry::appInit() /var/www/html/horde/imp/index.php:19
2. Horde_Registry->pushApp() /usr/share/pear/Horde/Registry.php:298
3. Horde_Registry->_pushAppError()
/usr/share/pear/Horde/Registry.php:1622
4. Horde_Registry::appInit() /var/www/html/horde/imp/index.php:19
5. Horde_Registry->pushApp() /usr/share/pear/Horde/Registry.php:298
6. Horde_Registry->callAppMethod()
/usr/share/pear/Horde/Registry.php:1617
7. Horde_Registry_Application->authenticated()
/usr/share/pear/Horde/Registry.php:1197
8. IMP_Application->_authenticated()
/usr/share/pear/Horde/Registry/Application.php:108
9. IMP_Auth::authenticateCallback()
/var/www/html/horde/imp/lib/Application.php:134
10. IMP_Auth::_log() /var/www/html/horde/imp/lib/Auth.php:252
11. IMP_Imap->__call() /var/www/html/horde/imp/lib/Auth.php:141
Details
The full error message is logged in Horde's log file, and is shown
below only to administrators. Non-administrative users will not see
error details.

Horde_Exception_PushApp Object
(
[application] => imp
[details] => 
[logged] => 1
[_logLevel:protected] => 0
[message:protected] => IMP is marked as authenticated, but no
credentials can be found in the session.
[string:Exception:private] => 
[code:protected] => 5
[file:protected] => /usr/share/pear/Horde/Registry.php
[line:protected] => 1679
[trace:Exception:private] => Array
(
[0] => Array
(
[file] => /usr/share/pear/Horde/Registry.php
[line] => 1622
[function] => _pushAppError
[class] => Horde_Registry
[type] => ->
)

[1] => Array
(
[file] => /usr/share/pear/Horde/Registry.php
[line] => 298
[function] => pushApp
[class] => Horde_Registry
[type] => ->
)

[2] => Array
(
[file] => /var/www/html/horde/imp/index.php
[line] => 19
[function] => appInit
[class] => Horde_Registry
[type] => ::
)

)

[previous:Exception:private] => Horde_Exception_AuthenticationFailure
Object
(
[application] => 
[code:protected] => 6
[details] => 
[logged] => 1
[_logLevel:protected] => 0
[message:protected] => IMP is marked as authenticated, but no
credentials can be found in the session.
[string:Exception:private] => 
[file:protected] => /var/www/html/horde/imp/lib/Imap.php
[line:protected] => 628
[trace:Exception:private] => Array
(
[0] => Array
(
[file] => /var/www/html/horde/imp/lib/Auth.php
[line] => 141
[function] => __call
[class] => IMP_Imap
[type] => ->
)

[1] => Array
(
[file] => /var/www/html/horde/imp/lib/Auth.php
[line] => 252
[function] => _log
[class] => IMP_Auth
[type] => ::
)

[2] => Array
(
[file] => /var/www/html/horde/imp/lib/Application.php
[line] => 134
[function] => authenticateCallback
[class] => IMP_Auth
[type] => ::
)

[3] => Array
(
[file] => /usr/share/pear/Horde/Registry/Application.php
[line] => 108
[function] => _authenticated
[class] => IMP_Application
[type] => ->
)

[4] => Array
(
[file] => /usr/share/pear/Horde/Registry.php
[line] => 1197
[function] => authenticated
[class] => Horde_Registry_Application
[type] => ->
)

[5] => Array
(
[file] => /usr/share/pear/Horde/Registry.php
[line] => 1617
[function] => callAppMethod
[class] => Horde_Registry
[type] => ->
)

[6] => Array
(
[file] => /usr/share/pear/Horde/Registry.php
[line] => 298
[function] => pushApp
[class] => Horde_Registry
[type] => ->
)

[7] => Array
(
[file] => /var/www/html/horde/imp/index.php
[line] => 19
[function] => appInit
[class] => Horde_Registry
[type] => ::
)

)

[previous:Exception:private] => 
)

)



I've googled around, but anything close to this issue seems to be
related to people managing Horde with c-panel or session storage
issues.  The Horde test page shows sessions working for both the
default PHP backend for storage, and database storage. 

Any ideas or suggestions on next steps would be appreciated.

Thanks, 
Rob