Airport Extreme - USB Disk as network disk for Windows and Mac, what format? I want to share a USB disk via Airport Extreme as a network disk for our Mac and Windows environment. To read and write on the disk, I've set it up as FAT32 (max 4GB files) and I can connect with it with all computers. 

The problem is now, when I add a file / folder.. it's being displayed for 2 seconds and it hides itself (as it doesn't exist). 

So, how should I format the USB disk so I can use it as network disk and write / read stuff on it?
From https://support.apple.com/en-us/HT202807


  Supported formats: Mac OS Extended (HFS-plus), FAT16, FAT32
  
  If HFS+ formatting is used, AFP and Microsoft SMB/CIFS protocols are
  used to share the device on the network. If a FAT16/32 format is used,
  only SMB/CIFS protocols are used and AFP won't be available.


So if you are using FAT32 and connecting to it from Mac and Windows using SMB it should work fine.