SQL Generic Error When Notes are Clicked

Hi,

I am using dynamic CRM 2015 version  7.0.1.129 on Premises.When user  click on notes in social pane.An error shows up which is "Generic SQL Error".

Here is the log

Unhandled Exception: System.ServiceModel.FaultException`1[[Microsoft.Xrm.Sdk.OrganizationServiceFault, Microsoft.Xrm.Sdk, Version=7.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35]]: Generic SQL error.Detail:
<OrganizationServiceFault xmlns:i="www.w3.org/.../XMLSchema-instance" xmlns="schemas.microsoft.com/.../Contracts">
<ErrorCode>-2147204784</ErrorCode>
<ErrorDetails xmlns:d2p1="schemas.datacontract.org/.../System.Collections.Generic" />
<Message>Generic SQL error.</Message>
<Timestamp>2016-04-12T17:00:52.6982705Z</Timestamp>
<InnerFault i:nil="true" />
<TraceText i:nil="true" />
</OrganizationServiceFault>

Actually the main issue is that the error is only showing for a single user not all of them and this happens every time when he click on Notes within a Pipeline Opportunity .Any kind of Help/Suggestion will be appreciated.

Thanks