I would like to share one of the incident which we faced recently on our production environment. Horde webmail stopped working for two Plesk servers with the below errors : A fatal error has occurred SQLSTATE[42S02]: Base table or view not found: 1146 Table 'horde.horde_prefs' doesn't exist Details have been logged for the administrator. Server details : Windows 2012 R2 Plesk Onyx 17.5.3 Horde version 5.x Steps to Fix it : Step 1 : This issue mostly happens if Horde database is missing or corrupt. In our case it was missing somehow ( may be deleted by some admin by mistake ) Step 2 : Once verified that database is missing from the MySQL, only option is to recreate the Database and Horde DB user by reinstalling it. Step 3 : To reinstall Horde, execute the below command : #Take a backup of PSA Database before making any DB related changes. plesk db dump PSA > C:\temp\PSA<Date>.sql #Removing the existing horde webmail setup ( In my case t...