Most Common Fix for DAX Driver errors in Windows Spring Update (1803) (You can do this!)

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As we continue to see high ticket rates related to the Windows Spring Update (often referred to as 1803), we can better recommend actions for our customers to take for fixing the problems.

The Most Common Problem

The most common problem is that the DAX Sound Device names are being mangled during the Spring Upgrade. The diagram below shows what a correct configuration of DAX should look like in the Device Manager:

After the Spring Update, here is what happened to one of my computers:

To list the problems with my installation, highlighted by the boxed entries, we find:
  1. We are missing 2 DAX IQ devices, that are present in the correct list. These are DAX IQ RX 2 and DAX IQ RX 4. Some of the mangled named devices are actually these two devices.
  2. We are missing 2 RESERVED IQ RX devices, DAX RESERVED IQ RX 2 and DAX RESERVED IQ 4. Again, some of the mangled named devices are actually these two devices.
  3. This system is one that I use PowerSDR on to test my Flex-3000 and use Virtual Audio Cables. You can see two of the VAC cables have been mis-named to DAX Audio TX and DAX MIC Audio.
Let's Fix This System!

If you see many multiple devices with the same name, feel uncomfortable in doing this procedure or just cannot figure out what to do, STOP! Create a trouble ticket and let Flex Technical Support work on your system.

Before we begin fixing these issues:

  1. Terminate SmartSDR and DAX. I know it sounds simple but I usually forget to do this! Double-check before you begin.
  2. Defeat your antivirus and malware software (as much as you can) during this process. Sometimes they will 'sandbox' these actions so they appear to be fixed but once you reboot, no changes are made.

To fix these, I will first right-click on the DAX Audio TX device that is a Virtual Audio Cable and select Uninstall Device. I will get the warning below, but will accept the risk and click Uninstall.

I will repeat this action for DAX Mic Audio device.

To fix the remaining items, I will open the Sound control panel app. When the Sound window opens, right click on it and you will see two items that are usually checked, 'Show Disabled Devices' and 'Show Disconnected Devices'. Uncheck them so we do not see these devices in our list (it will only confuse things!).

Now, click on the Playback tab in case it doesn't automatically open and scan for the name of the first erroneously titled device, which is DAX RESERVED AUDIO RX 2 which has the descriptor 'FlexRadio Systems DAX IQ'. Here you can see two of the mangled named devices in this window:

I will double-click on DAX RESERVED AUDIO 2 and see the property page below:

You notice that the device name is highlighted. I can now rename it to the proper name. Since I am missing a device that should be titled DAX RESERVED IQ RX 2 and this partially matches this device, I will assume its the one I am missing and rename it.

Press Apply, then press OK. You probably only need to press OK but I am a guy who wears belts and suspenders!

Look thru your list and see if any other devices are present that are mis-labeled. If so, repeat this procedure. You will see that the named device is partially correct, you only need to fix the part that isn't. I had a device called DAX RESERVED AUDIO RX 2 and renamed it DAX RESERVED IQ RX 2, for instance.

While you are in this window, make sure no DAX device is designated as the defaul playback device (green cirle with a white check-mark). If so, find the device for your speakers or headset and right-click on it, then select Default Device.

Now, click on the Recording Tab and perform the same action. By the picture below, I found DAX Audio RX 2 that is labeled as an IQ device:

Based on our approach from before, double-click it and rename it to DAX IQ RX 2.

Press Apply and OK and you have fixed another one!

Repeat for all the other misnamed devices you discovered in your examination of the Audio Inputs of the Device Manager.

Now, you have to reboot your system. If you do not, it will not work!

Once you reboot, go to the Device Manager control app and look under audio inputs and outputs, comparing it to the first picture above. It should be identical. If not, try the process again (we have had one customer report it took two tries to work on his system). After that, if it doesn't work, contact Flex Technical Support!

See you on the bands!
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Neal - K3NC, Employee

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Posted 3 weeks ago

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Greg Day, N8GD

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Hiring you was one of the smartest moves FlexRadio has made (not that Tim and others aren't competent).  Your extended knowledge of Windows and how it interfaces with Flex programs has proved to be an invaluable resource for all of us.  Thanks for providing this info to those of us who feel comfortable working "under the hood" of Windows.  I know it will greatly reduce the support load on the Flex organization.
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Tim - W4TME, Customer Experience Manager

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Who do you think is teaching him? ;-)
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Greg Day, N8GD

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Yeah, Tim.  That's why I put the disclaimer in parentheses regarding competency.  I know you're happy to have Neal's help, especially when things like the Win 10 1803 debacle come along.  Don't worry, you'll always be the "Mayor" here on the Community!
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Tim - W4TME, Customer Experience Manager

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I am the Exalted Grand PoohBah!  No lowly "mayor" for me :-D 
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Gary L. Robinson

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K1UO - Larry

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I would be happy to second that thought Greg.
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Matt NQ6N

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Does anyone know how these devices are being renamed or why Windows would decide to rename them to a different name than the one that was configured when they were installed?  Is there an identifier (other than the name) that remains correct/constant even when the update screws up the names? 
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Tim - W4TME, Customer Experience Manager

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What and why did Microsoft do what they did?  This is a question that is akin to knowing what is happening inside a black hole.  Seriously, they have code that is designed to "migrate" kernel mode drivers during an update.  These Win10 updates are in reality more like an operating system upgrade and if anyone has done Windows OS upgrades before, you know how brilliantly successful that went.

This is the new "normal" of having an operating system as a service; these updates will continue to mangle stuff and I'll be optimistic, eventually, fingers crossed, they will get better at it.  What we can do is what we have done and that is to mobilize our support resources, find workarounds and fix broken updates as fast as we can.  I know it isn't perfect, and it is frustrating for you as the user and several orders of magnitude more frustrating for FlexRadio Support and Engineering.
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Michael Walker, Official Rep

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Be aware that the Grand BooBah and his cronies haven't had much sleep in the last week.  And, no, I am not making this up. 

Imagine if this was mission critical applications, as that is the type of service they are providing.  As someone who has been in the Data Protection and Data Recovery business for decades, my hat is off to all of them.

Thanks guys!
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Bill W2PKY

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Does anyone know why an Uninstall and Reinstall does not correct the the names?
Sorry if I missed it.
I had several other issues with 1803; Printer driver and Meinberg needed to be reinstalled.
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Tim - W4TME, Customer Experience Manager

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Yes.  As part of the 1803 Update, Windows tries to "migrate" the DAX kernel-mode drivers and in doing so add a bunch of registry entries that were not added by the installer, so when the uninstaller runs, it does not remove entries that it does not know about.  It is the vestige of registry entries that have to be removed before the installer can re-install the DAX drivers correctly.
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Best explanation thanks Tim. It all makes sense now.

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Jerry - W2TXB

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Does the latest (i.e., yesterday's) update affect this problem in any way? I installed this update, and will, when time becomes available) check to see if anything (else) has changed with respect to SmartSDR, DAX, and VSP.

"May 8, 2018—KB4103721 (OS Build 17134.48) Applies to: Windows 10 version 1803

Improvements and fixes

This update includes quality improvements. No new operating system features are being introduced in this update. Key changes include:

  • Addresses an issue with the April 2018 Windows Servicing update that causes App-V Scripts (User Scripts) to stop working. 
  • Addresses an issue that may cause some devices to stop responding or working when using applications, such as Cortana or Chrome, after installing the Windows 10 April 2018 Update.

  • Addresses an issue that prevents certain VPN apps from working on builds of Windows 10, version 1803. These apps were developed using an SDK version that precedes Windows 10, version 1803, and use the public RasSetEntryProperties API.
  • Addresses additional issues with updated time zone information. 
  • Addresses an issue that may cause an error when connecting to a Remote Desktop server. For more information, see CredSSP updates for CVE-2018-0886.
  • Security updates to Windows Server, Microsoft Edge, Internet Explorer, Microsoft scripting engine, Windows app platform and frameworks, Windows kernel, Microsoft Graphics Component, Windows storage and filesystems, HTML help, and Windows Hyper-V.

If you installed earlier updates, only the new fixes in this package will be downloaded and installed on your device.

For more information about the resolved security vulnerabilities, see the Security Update Guide.

Known issues in this update

Microsoft is not currently aware of any issues with this update."
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Tim - W4TME, Customer Experience Manager

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I installed the patches yesterday and DAX and CAT are still working just fine on my test machine.  In general, these minor patches do not do the mayhem that an Update does.
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Rick Hadley - W0FG

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I installed this morning's update on both computers with no apparent corruption of the drivers, but I did have to do an additional reboot on both the computer and the radio to get DAX-IQ to recognize the panadaptors for CW Skimmer and DAX-AUDIO to WSJT-X.  Following the reboots all appears normal on both radios and computers.