In daily life, the sudden unsupported SD card may make you be at a loss. It may become blank and keeps asking to be formatted. In this article, you'll find free effective methods to fix the "unsupported SD card" error. And if they don't work, you can also download Bitwar data recovery here to recover data from the SD card, and then format the card to reuse.
 
Sometimes, the smartphones fail to read the SD Card and displays the following notification:
 

Unsupported SD card
This device doesn't support this SD card. Tap to set up in a supported format.

The "The SD card is Blank, and it keeps asking format" problem mostly happens to Android phone SD cards, Camera SD cards, memory cards or other USB drives, etc. The major causes are the SD card gets corrupted, unreadable, undetectable, damaged, or there exist some unknown/unwanted files or folders.
 
When it occurs, do you know how to fix? Sure, you know formatting would be the most direct method to fix blank SD card. But this will wipe out all the existing data and finally lead to serious data loss problem. Fortunately, full and safe solutions for the "SD card is blank or has some unsupported file system" error are offered here to help.
Solutions to fix Unsupported SD card

Before you carry out any rescue, please make sure that the SD card itself is in sound condition and can be detected by your computer. Only in this way, there is a necessity and possibility to fix this Unsupported SD card.
Solution 1: Try rebooting the phone

Although the operating system requires you to format the blank SD card, DON'T format it at once, try rebooting the phone at first. Then check if the SD card is normal.
Solution 2: Repeatedly insert and pull out the SD card

Try inserting and taking out the blank SD card several times, by these attempts your phone may finally read the SD card.
Solution 3: Run Chkdsk to fix errors

Some users had fixed this error by using CHKDSK, and maybe this way is also helpful to you.
 
Step 1: Connect Unsupported SD card with PC via card reader and make sure it is detected by the machine.
 
Step 2: Run CMD as administrator, and input chkdsk n: /f(n is the drive letter of the blank SD card) to fix errors.
 
Step 3: Put the SD card back to the phone and check whether the card works fine after that.

About another solutions，please read: 6 Solutions to Fix the SD Card Has the Unsure