The following error message is displayed in the Action Log on attempt to process an order for a Plesk-based subscription:
Process provisioning for document; Process document #1234567 Operation has failed with Error Code # -5. See Problem # p2016-09-19_12-44-26.1 for details.
While in the Problem Report related:
[2013/07/20 05:38:16] [DEBUG]  [HSPC::MT::Plesk::PleskGate::__send_request_to_agent] REPLY_DATA=<?xml version="1.0" encoding="UTF-8"?><packet version="126.96.36.199"><webspace><set><result><status>error</status><errcode>1019</errcode><errtext>PHP version cannot be specified because PHP support is not enabled</errtext><filter-id>3</filter-id><id>3</id></result></set></webspace></packet>
PHP Support option is disabled on Plesk side for the affected subscription while the subscription's hosting plan in OBAS has that option enabled.
PHP Support option for the affected subscription directly in Plesk and try to provision the order once again.