Quote from: Luke-Jr on September 06, 2013, 08:35:06 PM

Quote from: noncecents on September 06, 2013, 08:07:03 PM

On Windows it seems bfgminer doesn't know the difference between a problem with user access privileges and a device not responding/device sending back bad data due to a low power condition.

The error doesn't make sense on Windows since there's no user privileges restriction on non-storage USB devices.

I tested this by using a USB2.0 powered hub that doesn't provide enough power to operate Block Erupters and a USB3.0 hub that provides adequate power.

With the USB2.0 hub that did not provide enough power, when more than 2 block erupters were plugged in an error was reported by bfgminer on startup:

"Do not have user privileges required to open \\.\COMxx"

...where "xx" is a port number.

When I plugged the devices into a USB3.0 hub that provided adequate power for all the devices the error went away.

I was able to replicate this consistently by switching between the powered hubs.

This is an OS/driver issue. The message about user privs is shown when Windows reports ERROR_ACCESS_DENIED.

This is provably not a driver/OS issue.

If the same device is plugged into one hub it does not work and the error is presented. However, if it's unplugged and plugged into another hub it does work and the error is not presented.

If Windows is reporting ERROR_ACCESS_DENIED maybe Windows is reporting that error because of a problem that is different than the one you anticipated.

If you could anticipate every possible scenario there would never be bugs in your software and you'd be omnipotent.