MacBook Air won't read my flash drive

Hello C_S1997,

Thank you for reaching out to Apple Support Communities, and we'll be happy to help in any way we can. We understand you're having issues with yourMac reading our flash drivew. Follow the steps listed here to see if they resolve the issue: Connect and use other storage devices with Mac - Apple Support

"Connect and use other storage devices with Mac

External hard drives, thumb drives, USB drives, Flash memory cards, and devices like iPod are examples of storage devices that you can connect to your Mac using Thunderbolt, USB, or USB-C cables, or connect wirelessly using Bluetooth wireless technology.

Storage devices (such as external hard drives) can also be available on your network. Additionally, you can insert flash memory cards from your camera or other device in the SDXC card slot in your Mac. If your Mac doesn’t have a card slot, you can access the data on the flash memory card using a connected card reader. 

After you connect your storage device, you can move files from your Mac to the storage device or from your storage device to your Mac.

If your Mac has a USB-C port, see Use USB-C cables with your Mac.

Connect a storage device

• Connect the device to your Mac using the cable that came with it, then use the Finder to view the connected device.
• If the cable doesn’t have a connector that fits in your Mac, you may be able to use an adapter. See the documentation that came with the device.

Move files to or from an external storage device

1. Make sure your Mac is connected to the external storage device (for example, using a USB cable or over a network).
2. Click the Finder icon  in the Dock to open a Finder window, then do one of the following to move your files.

• Move files to the storage device: Select one or more files on the desktop or in a folder, then drag them to the storage device, listed below Locations in the Finder sidebar.
• Move files from the storage device: Select the storage device, listed below Locations in the Finder sidebar, then drag the files you want to a location on your Mac.

Get permission to view or work with files on a storage device

If you’re the administrator of the Mac, do one of the following:

• Authenticate as an administrator user: Depending on how you’re attempting to access the file, you may need to authenticate as an administrator user.
• Change Sharing & Permissions settings for the file: For instructions, see Set up file sharing on Mac.

If you’re not the administrator of the Mac, ask the administrator to give you access to the files you need.

Eject a storage device

On your Mac, do one of the following:

• Select the item to eject, then choose File > Eject.
• In the Finder sidebar, click the Eject button  next to the item’s name.
• On the desktop, drag the item that you want to eject to the Trash.

If you can’t eject a storage device, another app or user may be using one or more files on the storage device. See If you can’t eject a disk on Mac because an app is using it and If you can’t eject a disk because another user is using it."

We hope this helps.

Cheers!