Qualify a lead

When I try to qualify my leads, I get the below error.

Business Process Error
Attribute 'campaignid' cannot be NULL.

Any ideas how I can solve this one? Have googled it, without success.

<s:Envelope xmlns:s="schemas.xmlsoap.org/.../envelope"><s:Body><s:Fault><faultcode>s:Client</faultcode><faultstring xmlns:xml="www.w3.org/.../namespace" xml:lang="sv-SE">Attribute 'campaignid' cannot be NULL</faultstring><detail><OrganizationServiceFault xmlns="schemas.microsoft.com/.../Contracts"><ErrorCode>-2147220891</ErrorCode><ErrorDetails><KeyValuePairOfstringanyType><a:key xmlns:a="schemas.datacontract.org/.../System.Collections.Generic">OperationStatus</a:key><a:value xmlns:a="schemas.datacontract.org/.../System.Collections.Generic" xmlns:i="www.w3.org/.../XMLSchema-instance" i:type="b:int">0</a:value></KeyValuePairOfstringanyType><KeyValuePairOfstringanyType><a:key xmlns:a="schemas.datacontract.org/.../System.Collections.Generic">SubErrorCode</a:key><a:value xmlns:a="schemas.datacontract.org/.../System.Collections.Generic" xmlns:i="www.w3.org/.../XMLSchema-instance" i:type="b:int">-2146233088</a:value></KeyValuePairOfstringanyType></ErrorDetails><Message>Attribute 'campaignid' cannot be NULL</Message><Timestamp>2016-05-11T16:12:21.6733297Z</Timestamp><InnerFault><ErrorCode>-2147220891</ErrorCode><ErrorDetails><KeyValuePairOfstringanyType><a:key xmlns:a="schemas.datacontract.org/.../System.Collections.Generic">OperationStatus</a:key><a:value xmlns:a="schemas.datacontract.org/.../System.Collections.Generic" xmlns:i="www.w3.org/.../XMLSchema-instance" i:type="b:int">0</a:value></KeyValuePairOfstringanyType><KeyValuePairOfstringanyType><a:key xmlns:a="schemas.datacontract.org/.../System.Collections.Generic">SubErrorCode</a:key><a:value xmlns:a="schemas.datacontract.org/.../System.Collections.Generic" xmlns:i="www.w3.org/.../XMLSchema-instance" i:type="b:int">-2146233088</a:value></KeyValuePairOfstringanyType></ErrorDetails><Message>Attribute 'campaignid' cannot be NULL</Message><Timestamp>2016-05-11T16:12:21.6733297Z</Timestamp><InnerFault><ErrorCode>-2147220891</ErrorCode><ErrorDetails><KeyValuePairOfstringanyType><a:key xmlns:a="schemas.datacontract.org/.../System.Collections.Generic">OperationStatus</a:key><a:value xmlns:a="schemas.datacontract.org/.../System.Collections.Generic" xmlns:i="www.w3.org/.../XMLSchema-instance" i:type="b:int">0</a:value></KeyValuePairOfstringanyType><KeyValuePairOfstringanyType><a:key xmlns:a="schemas.datacontract.org/.../System.Collections.Generic">SubErrorCode</a:key><a:value xmlns:a="schemas.datacontract.org/.../System.Collections.Generic" xmlns:i="www.w3.org/.../XMLSchema-instance" i:type="b:int">-2146233088</a:value></KeyValuePairOfstringanyType></ErrorDetails><Message>Attribute 'campaignid' cannot be NULL</Message><Timestamp>2016-05-11T16:12:21.6733297Z</Timestamp><InnerFault xmlns:i="www.w3.org/.../XMLSchema-instance" i:nil="true" /><TraceText xmlns:i="www.w3.org/.../XMLSchema-instance" i:nil="true" /></InnerFault><TraceText xmlns:i="www.w3.org/.../XMLSchema-instance" i:nil="true" /></InnerFault><TraceText>
[Microsoft.Crm.ObjectModel: Microsoft.Crm.ObjectModel.SyncWorkflowExecutionPlugin]
[d5b86454-3a08-e511-80c6-0050568a0ae2: ]
Starting sync workflow 'Quick Source Camp', Id: d0b86454-3a08-e511-80c6-0050568a0ae2
Entering ConditionStep1_step:
Entering SetFieldRequiredLevelStep4_step:
Sync workflow 'Quick Source Camp' terminated with error 'Attribute 'campaignid' cannot be NULL'
</TraceText></OrganizationServiceFault></detail></s:Fault></s:Body></s:Envelope>