Unable to open domain hosting settings or file manager in Plesk: Full path is undefined

Symptoms

One of the following errors is displayed when opening Domains > example.com > Hosting Settings or Domains > example.com > File Manager after Plesk upgrade:

PLESK_ERROR: Internal error: Full path is undefined.
Message Full path is undefined.
File Webspace.php
Line 374
Type PleskFatalException

Or:

PLESK_ERROR: ERR (3) [panel]: PleskFatalException: Full path is undefined.
file: C:\plesk\admin\plib\Webspace.php
line: 374
code: 0

Or:

PLESK_ERROR: Error: New configuration files for the Apache web server were not created due to the errors in configuration templates: Template processing failed: file = /usr/local/psa/admin/conf/templates/default/domainVhost.php, error = Template_Exception: No data. file: /usr/local/psa/admin/plib/Template/Processor.php line: 28 code: 0 Previous error: Template_Variable_Exception: No data. file: /usr/local/psa/admin/plib/Template/Variable/AbstractCachedData.php line: 67 code: 0. Search in KB

Cause

Entries from the hosting table were removed due to the Plesk upgrade failure.

Resolution

1. Connect to the server via SSH/via RDP.

2. Create Plesk database backup.

3. Restore hosting table from pre-upgrade dump.

   On Linux the dump is located at '/var/lib/psa/dumps/preupgrade.*, on Windows at"%plesk_dir%\mysql\backup"or (in case if the database provider was different fom MySQL) at"%plesk_dir%\admin\db"` folder.

   On Linux in order to restore the table in MySQL extract the corresponding entries from the full dump via sed utility and use it to restore the table using the following commands:

   # gunzip /var/lib/psa/dumps/mysql.preupgrade.<version and time stamp>.dump.gz
   # sed -n -e '/DROP TABLE.*`hosting`/,/UNLOCK TABLES/p' /var/lib/psa/dumps/mysql.preupgrade.<version and time stamp>.dump > hosting.sql
   # MYSQL_PWD=cat /etc/psa/.psa.shadow mysql -u admin psa < hosting.sql

   On Windows the corresponding entries should be extracted manually using Notepad/Notepad++ utility and saved in a separate file, e.g. C:\hosting.sql. Then use the saved file to restore the table:

   C:\> "%plesk_dir%\Mysql\bin\mysql.exe" -uadmin -p<plesk_admin_password> -P8306 psa < C:\hosting.sql