An unknown issue caused the import of report content to fail or the value for CognosGateway0 is not correct. Another possibility is that the logon requirements for Cognos 8 are not available. You may already be logged onto this namespace, or the target namespace does not exist.
First, check the value of CognosGateway0. If this is correct, check that your report uses standard practices. Revise and resave the report, ensuring that text and images are not located in the same cell.