[repo_proxy 30] DocumentFacade::uploadBlob

I am trying to schedule a report from SAP WEBi Samples "Charting Report" with destination as  (Email) and am facing this error. Doesn't see like an Email configuration issue as it doesn't talk anything about SMTP errors.

here is the error:

Could not save the document to the repository for the following reason: [repo_proxy 30] DocumentFacade::uploadBlob - Query execute has failed : Error occurred while attempting to reconnect to CMS : Not a valid logon token. (FWB 00003) (hr=#0x80042a70) (WIS 30567)

I am using 4.1 SP4 . Can someone let me know what is the cause of this error?

Thanks