Hello Parismiss!
Welcome to The Canon Forums, and thank you for you!
If you have already verified that there are no paper jams or obstructions in the printer, ensured that the paper guides in the cassette are snug against the paper. If you are still experiencing the same issue, the printer will require servicing. Please click on the Contact Us link below to obtain your servicing options in your region.
We do not support printer models outside of the US. Printer model instructions may vary slightly. Please click the Contact Us above to contact Canon UK.
Thanks!