Remotely assisted PASI on checking the issue of check printing in NAV. Performed the print preview and printing of checks using the number series they have both prompted this error "An error occurred when loading the Report Print Preview window: The definition of the report '' is invalid.". After that I loaded the Object given by PASI and processed the same thing and the same issue is still occurring. As per their assessment they need to report this to their develop[er for further checking and modification. I will just follow up this in the following days.