Symptoms
Task 'Configuring "MailBox" for APS application WebHosting Plesk' failing with: "Error occurred during request to WHP API on service node 10.31.3.33: \" \"."
in logs:
/var/log/plesk/panel.log on whp14.poa.svr4u.net: [2019-06-29 19:08:29] ERR [extension/shm] Unable to set mailbox quota. Mailbox quota is incorrect (translated from Japanese)
/var/log/shm-dispatcher/dispatcher.log
[2019-06-29 19:23:03] app.ERROR: Execution context [PUT https://10.31.1.95:6301/web/MailBox/5b1388fb-1b2a-4a60-a4c5-3764773f097a (ID: 7ce7a121acb62351e47a3be109e4b33c92ec8c77)] Some errors have occurred while configuring mailbox: 'Error occurred during request to WHP API on service node 10.31.3.33: Unable to set mailbox quota. Mailbox quota is incorrect (translated from Japanese)
Cause
Software issue #WHM-10562 'Change of an unlimited mailbox size to default value leads to error' - fixed in 8.0
Resolution
Upgrade platform to the latest version.