A Plesk Client Order fails to provision with the error like
[2016/02/02 23:39:02] [DEBUG]  [HSPC::MT::Plesk::PleskGate::__send_request_to_agent] REPLY_DATA=<?xml version="1.0" encoding="UTF-8"?> <packet version="18.104.22.168"><client><set><result><status>error</status><errcode>1023</errcode><errtext>Unable to set limits: The current total value of domain limits for maximum number of IIS application pools is 1; requested 0.
[2016/02/02 17:27:24] [ERROR]  [HSPC::MT::BM::Subscription::PleskClientSubscription::provision_client_on_plesk] Unable to set limits: The current total value of domain limits for maximum number of databases is 18; requested 15.
There is a discrepancy between resources (IIS application pools, number of databases etc.) amount set in the hosting plan and those actually assigned to the Plesk Client on the Plesk node.
Either reduce resources amount on the Plesk node or increase them in the hosting plan.
For instance, to cope with IIS pools error please log in directly to Plesk and switch off the IIS Application Pool related to the Plesk Client in question. Please note that it will cause the customer's websites to run in a shared pool. To return the customer to a dedicated IIS pool, please buy a pool resource from the OBAS CP.