'Report Design not valid' Issue with Jasper Reports Server

[georgia.bloy]

Hi, last week after upgrading to Jaspersoft Studio 7.1.0 I ran a report in Jasper Reports Server which used to work fine but it gave me this error

Error Message: Report design not valid: 1. The detail section, the page and column headers and footers of the margins do not fit the page height

I haven't changed the sizes of anything (including sub-reports), but I've been through each one to make sure they're not bigger than the page height. It also works fine when I preview it within Jaspersoft Studio, has anyone else had this issue?

Thanks