Mark Berry August 5, 2016
I upgraded from Windows 7 Ultimate to Windows 10 Pro a couple weeks ago. I’ve had ongoing issues with briefly losing connection to my local network. Updating the network card and turning off power management wasn’t enough.
Eventually I noticed that I was getting hundreds of StorDiag errors. They were clumped in groups of about 11 every 10 seconds. Any time I see that many errors at once, I try to track it down because I know that can impact performance.
In the Event Viewer, these errors are buried under Applications and Services Logs > Microsoft > Windows > StorDiag > Microsoft-Windows-Storage-ClassPnP/Operational. I was getting two errors repeatedly:
504 Completing a failed IOCTL request.
507 Completing a failed non-ReadWrite SCSI SRB request
It’s important to look at the Details of the error. This pointed to a Generic Ultra-HS-SD/MMC device:
A little Googling confirms that this is an SD card reader. In my case it’s built in to my Dell U2410 monitor. Here it is in Device Manager:
It looks like Windows tried to migrate the device during the upgrade to Windows 10 on July 17:
I tried updating its driver but it says the latest is already installed:
There are several reports online about SD card readers that stopped working in Windows 10. As suggested in this article, I tried the Windows Troubleshooter for hardware, and I tried changing the drive letter of the device. Neither one helped. I did not have access to the original installer files (I believe they are built in to Windows), so I couldn’t try installing the driver in compatibility mode.
At this point I decided to just cut my losses and unplug the SD card reader from the computer. That meant unplugging the Dell monitor’s USB connection. I had to use another USB hub for other devices that had been using the monitor as a hub.
In any case, as soon the Dell monitor with its SD card reader was unplugged, the StorDiag errors stopped. We’ll see if that also helps my intermittent network connectivity issues.