We're sorry about the trouble. Would you mind telling us about the version of the operating system you are using in your phone/iPad pro? Are you getting any error messages? How much free space do you have on your device? Which version of the Creative Cloud Express Application you're using?
Please ensure you have stable internet. You may also try switching the internet connection. Also, try restarting the device after updating the Creative Cloud Express application to see if that makes any difference.