Hello,
I'm trying to stop and start call recording using IPOffice CTI Web Services, but start request always returns 500 error, what can be a problem?

Here are steps I take:

1. Login to Cti WS and subscribe to events (url: inyama/service/session)

2. Store ClientSessionId (received during login) and store callID (received in event notification message)

3. Send start call recording request (ClientSessionId added to http header) (url: /inyama/service/callcontrol/recordCall) body:

<ARSRecordCall xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.ecma-international.org/standards/ecma-323/csta/ed4">

                <connection xmlns="">

                                <callID xmlns="http://www.ecma-international.org/standards/ecma-323/csta/ed4">995eef7b-00c2-4299-a6dc-72fb6a30247c</callID>

                </connection>

                <requestingDevice switchingSubDomainInformationElements="31302E31302E37362E34" xmlns="">332</requestingDevice>

</ARSRecordCall>

The response always returns 500 Internal Server Error, body:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>

<ns3:Error xmlns:ns16="http://voicemailpro.common.avaya.com/" xmlns:ns17="http://calllog.common.avaya.com/" xmlns:ns14="http://conferencing.common.avaya.com/" xmlns:ns15="http://groups.system.common.avaya.com" xmlns:ns18="http://recording.common.avaya.com/" xmlns:ns9="http://com.avaya.common.csta.extended" xmlns:ns5="http://schemas.xmlsoap.org/ws/2004/09/transfer" xmlns:ns12="http://voicemail.avaya.com/" xmlns:ns6="http://conferencing.avaya.com/" xmlns:ns13="http://ccragent.common.avaya.com/" xmlns:ns7="http://com.avaya.inkaba.dal" xmlns:ns10="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ns8="http://com.avaya.inkaba.wstransfer" xmlns:ns11="http://voicemail.common.avaya.com/" xmlns:ns2="http://www.ecma-international.org/standards/ecma-323/csta/ed4" xmlns:ns4="http://schemas.xmlsoap.org/ws/2004/08/addressing" xmlns:ns3="http://openapi.common.avaya.com/">

                <errorCode>SERVER_PROBLEM</errorCode>

                <errorValue>java.lang.NullPointerException</errorValue>

</ns3:Error>

The stop recording request doesn't return error, (ClientSessionId added to http header) (url:/inyama/service/callcontrol/stopRecordCall), body:

<ARSStopRecordCall xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.ecma-international.org/standards/ecma-323/csta/ed4">

                <connection xmlns="">

                                <callID xmlns="http://www.ecma-international.org/standards/ecma-323/csta/ed4">02b223e4-c1d2-48a1-9ded-109ae9094ba6</callID>

                </connection>

</ARSStopRecordCall>

Response 202 Accepted, body:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>

<ns2:ARSResponse xmlns:ns16="http://voicemailpro.common.avaya.com/" xmlns:ns17="http://calllog.common.avaya.com/" xmlns:ns14="http://conferencing.common.avaya.com/" xmlns:ns15="http://groups.system.common.avaya.com" xmlns:ns18="http://recording.common.avaya.com/" xmlns:ns9="http://com.avaya.common.csta.extended" xmlns:ns5="http://schemas.xmlsoap.org/ws/2004/09/transfer" xmlns:ns12="http://voicemail.avaya.com/" xmlns:ns6="http://conferencing.avaya.com/" xmlns:ns13="http://ccragent.common.avaya.com/" xmlns:ns7="http://com.avaya.inkaba.dal" xmlns:ns10="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ns8="http://com.avaya.inkaba.wstransfer" xmlns:ns11="http://voicemail.common.avaya.com/" xmlns:ns2="http://www.ecma-international.org/standards/ecma-323/csta/ed4" xmlns:ns4="http://schemas.xmlsoap.org/ws/2004/08/addressing" xmlns:ns3="http://openapi.common.avaya.com/"/>

Software versions:
Avaya IP Office 10.1 server edition; Version: 10.1.6.0 build 7

Any help appreciated. Thanks.