Exfat unable to write / delete files

[story]

I was using a MBP 2012 10.11 and I've been writing files to an external 128GB MicroSD with Built-in card slot. I've moved to a MBPr 2013 10.11 and the same card cannot be written to.

Works:
1. 64GB Exfat Card with Built-in slot
2. 128GB Exfat Card with external card reader
3. 128GB Exfat Card in Parellel

Not Working:
1. 128GB Exfat with Built-in slot

I am lost, I don't know how to fix it.

 

[JohnDS]

Try running Repair Disk on it from Disk Utility

 

[story]

Try running Repair Disk on it from Disk Utility

SOLVED
I ran First Aid and it works now.

 

[howiest]

When I read the thread title I thought it meant that you used to be overweight, and you'd lost admin privileges on your computer.

 

[JohnDS]

Or maybe, has lost weight but is still illiterate.