It's possible Risport does not like the order of the elements in the CmSelectionCriteria - the WSDL defines a sequence such as the following (tested on my UCM 8.5(1) system
<soapenv:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ris="http://ccm.cisco.com/serviceability/soap/risport70/">
<soapenv:Body>
<SelectCmDevice>
<CmSelectionCriteria>
<MaxReturnedDevices>200</MaxReturnedDevices>
<Class>Any</Class>
<Model>255</Model>
<Status>Any</Status>
<SelectBy>Name</SelectBy>
<SelectItems>
<Item>*</Item>
</SelectItems>
</CmSelectionCriteria>
</SelectCmDevice>
</soapenv:Body>
</soapenv:Envelope>