Import Failed - Multiple Step Operation generated errors

I have modified a report for a customer on my local copy of SI. I have exported the modified report which has some additional parameter fields & filters on 3 of the sub-reports.

When I re-import the modified report on the customer site, I use the existing connection when prompted, then for the 3 containers that have the additional parameter field & filters, I select No to create a new container, when prompted. For the unchanged containers, I select Yes, but at the end of the import I get an error
"Import Failed - Multiple Step Operation generated errors. Check each status value".

How / where do I check the status value?

What is the fix to import the updated report correctly?

I have tried answering No and creating a new uniquely named containers for all sub-reports but get the same error at the end. I was hoping that the export / import option would avoid the need to apply the changes step by step on the customer site.

I am logged in as a user with ADM access and can run both the Report Manager & Connector OK.

Thanks.

Colin