Unable to log into Horde webmail from a particular email account:
A fatal error has occurred Horde_Prefs_Scope::serialize() must return a string or NULL
Details have been logged for the administrator
JSON string in Horde database is corrupted. For example, it contains a Unicode character(s).
# plesk db dump horde > horde.$(date +%F_%R).sql
plesk db dump horde > C:horde_dump.sql
Delete all entries from
horde_prefstable that are related to the affected email account:
Warning: This will delete configurations that were set in Horde UI for this user and they should be recreated anew.
[email protected]with the affected email account name.
# plesk db “DELETE FROM horde.horde_prefs WHERE
pref_uid= ‘[email protected]’;”