plesk 12 horde geeft A fatal error has occurred voor 1 domainnaam alle andere werken

plesk 12 horde geeft de volgende melding na het aanmelden:
A fatal error has occurred
Call to a member function write() on a non-object
Details have been logged for the administrator.

Alle andere domainnamen werken wel correct

2015-11-25T08:37:18+00:00 DEBUG: HORDE [horde] SQL (0,0004s)
SELECT alarm_id, alarm_uid, alarm_start, alarm_end, alarm_methods,
alarm_params, alarm_title, alarm_text, alarm_snooze, alarm_internal
FROM horde_alarms WHERE alarm_dismissed = 0 AND ((alarm_snooze IS NULL
AND alarm_start <= '2015-11-25 08:37:18') OR alarm_snooze <=
'2015-11-25 08:37:18') AND (alarm_end IS NULL OR alarm_end >=
'2015-11-25 08:37:18') AND (alarm_uid IS NULL OR alarm_uid = '' OR
alarm_uid = '') ORDER BY alarm_start, alarm_end [pid 7528 on line 238 of "/usr/share/psa-pear/pear/php/Horde/Db/Adapter/Pdo/Base.php"]
2015-11-25T08:37:18+00:00 DEBUG: HORDE [horde] Load config file (motd.php; app: horde) [pid 7528 on line 109 of "/usr/share/psa-pear/pear/php/Horde/Registry/Loadconfig.php"]
2015-11-25T08:37:18+00:00 DEBUG: HORDE [horde] Max memory usage: 5505024 bytes [pid 7528 on line 609 of "/usr/share/psa-pear/pear/php/Horde/Registry.php"]
tail: /var/log/psa-horde/psa-horde.log: file truncated
2015-11-25T08:37:29+00:00 DEBUG: HORDE Load config file (conf.php; app: horde) [pid 7528 on line 109 of "/usr/share/psa-pear/pear/php/Horde/Registry/Loadconfig.php"]
2015-11-25T08:37:29+00:00 DEBUG: HORDE [imp] Load config file (conf.php; app: imp) [pid 7528 on line 109 of "/usr/share/psa-pear/pear/php/Horde/Registry/Loadconfig.php"]
2015-11-25T08:37:29+00:00 DEBUG: HORDE [imp] Load config file (backends.php; app: imp) [pid 7528 on line 109 of "/usr/share/psa-pear/pear/php/Horde/Registry/Loadconfig.php"]
2015-11-25T08:37:29+00:00 EMERG: HORDE [imp] Call to a member function write() on a non-object [pid 7528 on line 4426 of "/usr/share/psa-pear/pear/php/Horde/Imap/Client/Socket.php"]
2015-11-25T08:37:29+00:00 DEBUG: HORDE 1. Horde_ErrorHandler::catchFatalError()

@maverh
Zou dit het kunnen zijn:
http://kb.odin.com/en/122453

De file /usr/share/dhparams.pem bestaat en is correct.

Deze ook gezien?
http://kb.odin.com/en/126223

Beide verklaren niet echt waarom je het met maar 1 domeinnaam hebt. Maar deze tweede link geeft wel exact hetzelfde weer in de logfile.

Waar staan de individuele configuratie files voor elk domain? Ik vermoed dat daar het probleem zit.

http://kb.odin.com/en/126223
heb ik ook geïnstalleerd maar geeft geen oplossing