Reader can not open pdf in USB disk.

[212777932228412355oyz]

my Reader can't be open the pdf which is in the USB disk and make the protection for USB. current reader version is 21.011.20039.

I checked old pdf version in the old Reader version some month ago, that's no any issues. 

other person/ PC can open the pdf files also. other pdf reader is good also.

when I deinstalled the Reader APP, and try to reinstall,but can not find the APP to download.

Adobe Acrobat Reader DC and Adobe Acrobat DC both can not open the files in USB. the version is same, which is autoupgrade some days ago.

[Bernd Alheit]

Try this:

Copy the file to a local disc and open it.

[212777932228412355oyz]

I need to verify it can be open normally from USB. could you support to clarify what's the reason for the disable. Thanks

[Bernd Alheit]

I have no issue with USB drives.

[Test Screen Name]

Is this a protected/passworded USB?

Mac or Windows?

is it a WD disk?