Unable to change the value of PHP settings in Plesk: Call to a member function updateUser() on null

Symptoms

Unable to change PHP Settings (e.g. memory_limit ) in Plesk > Domains > example.com . The following error appears in Plesk UI:

PLESK_ERROR: Internal error.
ERROR: Call to a member function updateUser() on null (Abstract.php:1020)

Cause

Database inconsistency. There are no corresponding records in the table psa.ServiceInstances for the separate domain example.com or for all domains.

Resolution

If the issue is present for multiple domains do the following:

1. Connect to the server using SSH.

2. Create a backup of psa database:

   # plesk db dump psa > /root/psa_dump.sql

3. Run the following commands:

   # MYSQL_PWD=`cat /etc/psa/.psa.shadow` mysql -u admin psa -N -e "select id from domains;" > list.txt
   # while read line; do
   I=$line;
   A=`uuidgen`;
   plesk db "INSERT INTO ServiceInstances (serviceInstallationId, servicePackageId, reference, status, enabled) values (1, $I, '$A', 1, 1)";
   A=`uuidgen`;
   plesk db "INSERT INTO ServiceInstances (serviceInstallationId, servicePackageId, reference, status, enabled) values (2, $I, '$A', 1, 1)";
   done < list.txt

If the issue is present for only one domain example.com follow these steps:

1. Connect to the server using SSH.

2. Create a backup of psa database:

   # plesk db dump psa > /root/psa_dump.sql

3. Find records in the table psa.ServiceInstallations :

   # plesk db -e "SELECT * FROM ServiceInstallations" 
   +----+-----------------+--------+---------------+
   | id | name            | status | serviceNodeId |
   +----+-----------------+--------+---------------+
   |  1 | PleskDns        |    1   |        1      |
   |  2 | PleskFileSystem |    1   |        1      |
   +----+-----------------+--------+---------------+

4. Find id of the domain example.com .

   # plesk db "SELECT s.id, d.name FROM Subscriptions AS s LEFT JOIN domains AS d ON s.object_id=d.id WHERE d.name='example.com'"
   +----+-----------------+
   | id |       name      |
   +----+-----------------+
   | 14 |   example.com   |
   +----+-----------------+

   Note : replace the domain example.com with an actual domain name from the previous step.

5. Make sure that there are no records related to the domain example.com (if corresponding records are contained, contact Plesk technical support)

   # plesk db "SELECT * FROM ServiceInstances WHERE servicePackageId='14';"

   Note : replace id of the domain example.com with id of the actual domain name from the step 2.

6. Сreate corresponding records in the table psa.ServiceInstances manually for each record from the table psa.ServiceInstallations :

   # plesk db "INSERT INTO ServiceInstances (serviceInstallationId, servicePackageId, reference, status, enabled) values (1, 14, UUID(), 1, 1)"
   # plesk db "INSERT INTO ServiceInstances (serviceInstallationId, servicePackageId, reference, status, enabled) values (2, 14, UUID(), 1, 1)"

   where:

   serviceInstallationId is id of the service from the table psa.ServiceInstallations from the step 1.

   servicePackageId is id of the domain example.com from the step 2.

   reference is uuid generated by execution of the command uuidgen.