USB Drives not working

Please read the following user tip and restate your question/problem in detail: 

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How are the drives connected to your MBP?

How are the drives formatted?

Do you have External Discs checked in Finder's General settings pane?

Have you installed and run any "cleaning", "optimizing", "speed-up", anti-virus or VPN apps on your Mac?

More information is needed. Are the drives used for storage, backup? It could be a formatting issue. Does your Mac see them when using Disk Utility? Were they initially formatted with the vendor's maintenance utility app? That can cause problems.

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