My epson stylus R240 printer is showing some error.

At some point you have directed it to print from an sd card and its informing you theres no sd card in the machine and you need to insert it . you need to go into your settings and close this process . If you cant find the proper route to go back then simply shut the machine off and unplug for a minute to clear the printer cache , then clear your que in the printer properties on your computer. Hope this helps