Creating subscription by API request fails with error status, however subscription created with no hosting

For the first issue change the username testusername123456 according to the following requirements:

It is possible to use lowercase alphanumeric, dash, and underscore symbols in the username. The username should start with a lowercase alphabetic character and should be between 1 and 16 characters in length.

For example, the username testusername123456 consists of 18 characters, while the maximum characters for username are limited 16. To solve the issue for this case, it is needed to remove 2 characters.

For the second issue, as a workaround, manually remove the partly created subscription in Plesk and then recreate it via WHMCS.

• Connect to the server using SSH.

• Check the file /etc/passwd if the user from the error exists there and delete all found lines:

  # grep testuser /etc/passwd
  testuser:x:10340:1003::/var/www/vhosts/example.com:/bin/false

• Create Plesk database backup

• Access Plesk database and remove all orphaned records from the Plesk database according to the following example:

  # plesk db
  mysql> select * from sys_users where login like "%testuser%";
  +-----+---------------+-----------------+------------+-------------------------------+------------+-------+-----------+
  | id | serviceNodeId | login | account_id | home | shell | quota | mapped_to |
  +-----+---------------+-----------------+------------+-------------------------------+------------+-------+-----------+
  | 411 | 1 | testuser | 2690 | /var/www/vhosts/example.com | /bin/false | 0 | NULL |
  | 416 | 1 | testuser | 2702 | /var/www/vhosts/example.com | /bin/false | 0 | NULL |
  +-----+---------------+-----------------+------------+-------------------------------+------------+-------+-----------+
  
  mysql> select * from web_users where sys_user_id=411 OR sys_user_id=416;
  Empty set (0.00 sec)
  mysql> select * from ftp_users where sys_user_id=411 OR sys_user_id=416;
  Empty set (0.00 sec)
  mysql> select * from hosting where sys_user_id=411 OR sys_user_id=416;
  Empty set (0.00 sec)
  mysql> select * from ScheduledTasks where sysUserId=411 OR sysUserId=416;
  Empty set (0.00 sec)
  mysql> select * from subdomains where sys_user_id=411 OR sys_user_id=416;
  Empty set (0.00 sec)
  mysql> select * from accounts where id=2690 OR id=2702;
  +------+------+----------------------------------------------------------------+
  | id | type | password |
  +------+------+----------------------------------------------------------------+
  | 2690 | sym | $AES-128-CBC$Q1AgXs3iTyjYsDpBFeOvRw==$OCZVaOCBMWG2+dQ2uDOeRQ== |
  | 2702 | sym | $AES-128-CBC$+vbXTORYdJuoWO7s4jXyLA==$f39OnbhjobEtY/I+i0ypMQ== |
  +------+------+----------------------------------------------------------------+
  2 rows in set (0.00 sec)
  mysql> delete from accounts where id=2690 OR id=2702;
  Query OK, 2 rows affected (0.00 sec)
  mysql> delete from sys_users where id=411 OR id=416;
  Query OK, 2 rows affected (0.00 sec)