unable to delete managed solution in crm online

Unhandled Exception: System.ServiceModel.FaultException`1[[Microsoft.Xrm.Sdk.OrganizationServiceFault, Microsoft.Xrm.Sdk, Version=8.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35]]: There should be at least one entity returned. Count: 0Detail:
<OrganizationServiceFault xmlns:i="www.w3.org/.../XMLSchema-instance" xmlns="schemas.microsoft.com/.../Contracts">
<ErrorCode>-2147220970</ErrorCode>
<ErrorDetails xmlns:d2p1="schemas.datacontract.org/.../System.Collections.Generic" />
<Message>There should be at least one entity returned. Count: 0</Message>
<Timestamp>2016-07-18T04:22:09.6876916Z</Timestamp>
<InnerFault i:nil="true" />
<TraceText i:nil="true" />
</OrganizationServiceFault>