{Error Resolution}Record is Unavailable error in Dynamics CRM 2015

Recently in our project we were getting the following error, whenever users will try and open the record will be given

Record is unavailable pop-up.

Unhandled Exception: System.ServiceModel.FaultException`1[[Microsoft.Xrm.Sdk.OrganizationServiceFault, Microsoft.Xrm.Sdk, Version=7.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35]]: System.Web.HttpUnhandledException: Microsoft Dynamics CRM has experienced an error. Reference number for administrators or support: #F8833B04Detail:
<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>System.Web.HttpUnhandledException: Microsoft Dynamics CRM has experienced an error. Reference number for administrators or support: #F8833B04</Message>
  <Timestamp>2015-09-14T01:36:28.2122414Z</Timestamp>
  <InnerFault>
    <ErrorCode>-2147220969</ErrorCode>
    <ErrorDetails xmlns:d3p1=”schemas.datacontract.org/…/System.Collections.Generic” />
    <Message>account With Id = 4f8cc581-0ab9-e211-9e1e-005056b30010 Does Not Exist</Message>
    <Timestamp>2015-09-14T01:36:28.2122414Z</Timestamp>
    <InnerFault i:nil=”true” />
    <TraceText i:nil=”true” />
  </InnerFault>
  <TraceText i:nil=”true” />
</OrganizationServiceFault>

Resolution: We noticed that we had implemented a Job in multi-threaded mode running on the set of entities.

Turning it to single thread solved the issue.

Secondly, clearing cache and re-logging into the system also helped resolve the issue.