USB Camera conflict with my reader

When my reader driver is working well, if user tried to download photo from
a USB camera, the system pop out message

When my reader driver is working well, if user tried to download photo from
a USB camera, the system pop out message

When my reader driver is working well, if user tried to download photo from
a USB camera, the system pop out message

Error message: "Action cannot be completed because another program is busy.

Click Active to switch to this program and to solve the problem. (buttons:

Activate, Retry"

Is there something wrong in my usb reader driver? What’s the possible
problem?

Haikun