Application server when connects to Crystal report server through f5 load balancer gives error

We have a application server that connects to f5 load balancer and then to a four node SAP cluster. We can see the reports directly from application server to the Crystal report server. We can also see the reports directly from f5 load balancer IP to the Crystal report server. But when the application access the crystal report via the f5 load balancer it throws the below error message: "Unable to access the CMS . A wrong connect is made to .....CrystalDecisions.Enterprise.Internal.SessionMgrClass.Logon....reportviewer.Page_load in ReportViewer.aspx.cs:line 70"