MakerBot Print is our newest print-prepration software, which supports native CAD files and STL assemblies,
allows you to interact with all your printers via the Cloud, and many other exciting new features.
Is this your 300x300 bed?
did you left the 313mm (X) x 364mm (Y) extrusions? or did you increased the size of the x/y extrusions?
what Y carriage plate are you using for the 300mm x 300mm hotbed?