episerver failed to copy page exception: content with guid "00000000-0000-0000-0000-000000000000" was not found - using 7.5

Hi,

When I copy and paste a page in the CMS (version 7.5) I get the following error pop up:

episerver failed to copy page exception: XXXX {page name} content with guid "00000000-0000-0000-0000-000000000000" was not found

Does anyone have any ideas on how I can fix this?

Thanks

Jon