I found a solution:
WARNING! THIS MIGHT FORMAT YOUR SDCARD!
Put your micro sdcard in an android device and once it says ''new sdcard detected'' in the notifications, click on it and either format it for apps and stuff (if you dont care about what it contains) or skip this step.Now go into settings and find storage and usb, click it and find the sd card and click it. Now press the menu button and click ''mount as a movable device'' or something like that. Put it in your reader and you should be good to go!