Horde: no folders showing

[drdr6]

I've been missing folders in horde since my last update some while back. It's recently become relevant since my son started trying to use Horde as his webmail client.

Symptoms are:
When logging on, the screen goes blank, requires a browser reload
Folders pane down left side blank
"rebuild folder tree" does nothing
Folders dropdown menu contains nothing

Inbox working exactly as expected, new mail / send working ok
dovecot working fine to external imap clients; can see all folders etc. with no problems.


in the apache logs:
[error] PHP Fatal error: Cannot redeclare class Ingo_Storage_blacklist in /usr/share/horde3/ingo/lib/Storage.php on line 543, referer: http://b3/pim/imp/login.php
[error] PHP Notice: Undefined index: filteravail in /usr/share/horde3/imp/mailbox.php on line 205, referer: http://b3/pim/imp/login.php
[error] PHP Warning: reset() expects parameter 1 to be array, null given in /usr/share/horde3/imp/lib/IMAP/Tree.php on line 249, referer: http://b3/pim/imp/login.php

[error] PHP Notice: Undefined index: showunsub in /usr/share/horde3/imp/lib/IMAP/Tree.php on line 469, referer: http://b3/pim/imp/login.php
[error] PHP Warning: Invalid argument supplied for foreach() in /usr/share/horde3/imp/lib/IMAP/Tree.php on line 492, referer: http://b3/pim/imp/login.php
[error] PHP Warning: Invalid argument supplied for foreach() in /usr/share/horde3/imp/lib/IMP.php on line 1255, referer: http://b3/pim/imp/login.php
[error] PHP Warning: Invalid argument supplied for foreach() in /usr/share/horde3/imp/lib/IMP.php on line 1255, referer: http://b3/pim/imp/login.php
[error] PHP Warning: explode(): Empty delimiter in /usr/share/horde3/imp/lib/IMAP/Tree.php on line 406, referer: http://b3/pim/imp/login.php
[error] PHP Notice: Undefined index: % in /usr/share/horde3/imp/lib/IMAP/Tree.php on line 1382, referer: http://b3/pim/imp/login.php
[error] PHP Notice: Undefined index: tasklistavail in /usr/share/horde3/imp/lib/IMP.php on line 520, referer: http://b3/pim/imp/login.php
[error] PHP Notice: Undefined index: notepadavail in /usr/share/horde3/imp/lib/IMP.php on line 537, referer: http://b3/pim/imp/login.php
[error] PHP Warning: Invalid argument supplied for foreach() in /usr/share/horde3/imp/lib/IMP.php on line 1288, referer: http://b3/pim/imp/login.php
[error] PHP Warning: Invalid argument supplied for foreach() in /usr/share/horde3/imp/lib/IMP.php on line 1255, referer: http://b3/pim/imp/login.php
[error] PHP Warning: Invalid argument supplied for foreach() in /usr/share/horde3/imp/lib/IMP.php on line 1255, referer: http://b3/pim/imp/login.php
(previous 3 lines repeat 4x)

[error] PHP Warning: Invalid argument supplied for foreach() in /usr/share/horde3/imp/lib/IMP.php on line 1288, referer: http://b3/pim/imp/mailbox.php?mailbox=I ... il_popup=1
[error] PHP Warning: Invalid argument supplied for foreach() in /usr/share/horde3/imp/lib/IMP.php on line 1255, referer: http://b3/pim/imp/mailbox.php?mailbox=I ... il_popup=1
[error] PHP Warning: Invalid argument supplied for foreach() in /usr/share/horde3/imp/lib/IMP.php on line 1255, referer: http://b3/pim/imp/mailbox.php?mailbox=I ... il_popup=1
(and repeats again)

[error] PHP Notice: Undefined index: filteravail in /usr/share/horde3/imp/mailbox.php on line 205, referer: http://b3/pim/imp/mailbox.php?mailbox=I ... il_popup=1
[error] PHP Notice: Undefined index: tasklistavail in /usr/share/horde3/imp/lib/IMP.php on line 520, referer: http://b3/pim/imp/mailbox.php?mailbox=I ... il_popup=1
[error] PHP Notice: Undefined index: notepadavail in /usr/share/horde3/imp/lib/IMP.php on line 537, referer: http://b3/pim/imp/mailbox.php?mailbox=I ... il_popup=1

[error] PHP Notice: Undefined index: showunsub in /usr/share/horde3/imp/lib/IMAP/Tree.php on line 469, referer: http://b3/pim/services/prefs.php?app=imp&group=display
[error] PHP Warning: Invalid argument supplied for foreach() in /usr/share/horde3/imp/lib/IMAP/Tree.php on line 492, referer: http://b3/pim/services/prefs.php?app=imp&group=display
[error] PHP Warning: explode(): Empty delimiter in /usr/share/horde3/imp/lib/IMAP/Tree.php on line 406, referer: http://b3/pim/services/prefs.php?app=imp&group=display
[error] PHP Notice: Undefined index: filteravail in /usr/share/horde3/imp/mailbox.php on line 205, referer: http://b3/pim/services/prefs.php
[error] PHP Notice: Undefined index: % in /usr/share/horde3/imp/lib/IMAP/Tree.php on line 1382, referer: http://b3/pim/services/prefs.php
[error] PHP Notice: Undefined index: tasklistavail in /usr/share/horde3/imp/lib/IMP.php on line 520, referer: http://b3/pim/services/prefs.php
[error] PHP Notice: Undefined index: notepadavail in /usr/share/horde3/imp/lib/IMP.php on line 537, referer: http://b3/pim/services/prefs.php
[error] PHP Notice: Undefined index: showunsub in /usr/share/horde3/imp/folders.php on line 53, referer: http://b3/pim/imp/mailbox.php?mailbox=INBOX
[error] PHP Notice: Undefined index: % in /usr/share/horde3/imp/lib/IMAP/Tree.php on line 1382, referer: http://b3/pim/imp/mailbox.php?mailbox=INBOX
[error] PHP Warning: reset() expects parameter 1 to be array, null given in /usr/share/horde3/imp/lib/IMP.php on line 1246, referer: http://b3/pim/imp/mailbox.php?mailbox=INBOX
[error] PHP Warning: key() expects parameter 1 to be array, null given in /usr/share/horde3/imp/lib/IMP.php on line 1247, referer: http://b3/pim/imp/mailbox.php?mailbox=INBOX

I've tried finding horde IMAP configuration, wondering how horde knows what folders to subscribe to (asking for the subscribe option in a horde session produces an empty list)

Anyone recognize the symptoms ? Or how to turn on any debugging ?

I find Horde's (lack of documentation) exasperating. Is there a proper configuration guide / explanation available anywhere ?

Thanks

[drdr6]

I've come to the conclusion that the problem with folders and the initial login all lie within the Horde section of the mysql database.

Uninstalling and re-installing horde didn't fix the problem (and made a right mess of the machine since uninstallling bubba-horde pulls out bubba-backend, but reinstalling it doesn't put it back in)

I had several ocurrences of the administrator password for "root" not being the current administrator password for root, or blank.

What's the cast-iron way to remove horde and horde-users from the mysql database and re-initialize it so I can get to the administrator tab again ?

I see other tips like:
signal-event post-install; signal-event reboot, but signal-event does not appear to be installed any more than config show horde does

This probably ties in with all the problems I've had with bubba-album; seems like I need to be able to completely re-built the database.