What causes the error "No certificate found in USB storage." when trying to import a certificate? I have a Samsung S3 with Android 4.04 and to get on my WiFi at work I need to install a certificate .p12 file.  So, I navigate to "Security and lock screen"-->"Install from device storage."  BUT instead of giving me a field to specify the location of my cert ( on /mnt/extSdCard )  it just says "No certificate found in USB storage."

There are some USB devices ( called "UsbDriveA" through "UsbDriveF" in my /mnt folder) but I cannot copy the cert onto them because they are read-only.

So, how do I get this certificate imported?  I tried using "Android Certificate Installer" from the app store and that didn't work for me either: it launches a browser and the browser fails to prompt for the cert password.
I figured out a workaround.  The workaround is to download a File Manager tool and then double click the .p12 cert, which opens up and prompts for the password.   I still don't know why the control panel doesn't do what it suggests, but at least I found a solution.