Reporting Error

Hi All

For the last few days i've had a issue where sometimes i can run a report then others i get a Reporting Error. The report cannot be displayed (rsProcessingAborted)

It makes no sense i can click the X in the top corner and run again and it's fine the error has gone then other times i can click the report 10 times with no luck then all of a sudden it works again

Any ideas what could cause this

Kind Regards