Q: Microsoft Office files won't open from usb

I've bought a new USB to use for work files. It's a SanDisk 32GB USB.

For a while, it would not open Microsoft Office files on my Mac. Then a few weeks ago, it fixed itself and was working fine.

However it has now reverted back to not opening again. When I drag it off the USB, it opens with no problems however, I would like to solve this as consantly dragging files off the USB to open them is inconvenient.

There are also three different messages for Word, Excel and Powerpoint.

I've posted a screen-cap of each below

Word:

Excel:

PowerPoint:

Any help or advice with this matter would be greatly appreciated.

Thank you.