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prrtcls.sys or pagefault in non paged area

TomHammack Member ✭✭
edited June 2020 in DAX
I keep getting the BSOD with the following errors. (My spelling of the error may be wrong, but I think it is close enough for the techies to figure out what I am trying to say.....I hope.

portcls.sys or
pagefauilt in non paged area

Flex 6700.Serial: 2017-5331-6700-8538, Max Licensed Version: v3, Radio ID: 00-1C-2D-02-0D-02, Radio IP:, Radio Internet: Available, Radio Firmware: v3.1.12.51

The page fault error is a long time problem. The portcls error I believe is a new one for me.

The seem to occur after I have made a change in the CAT settings. (At least recently, it has not wiped out the port settings in CAT.)

Hopefully there is a fix for whatever I am doing wrong.


  • K1VL
    K1VL Member ✭✭
    edited June 2020
    portcls.sys usually relates to audio system drivers. I have gotten these BSOD in Windows upgrades. A few reboots cleared up my issue. If it doesn’t for you I would suggest updating your audio drivers to the latest version. You can check with your computer vendor’s web site for the latest versions.
  • RoyS
    RoyS Member ✭✭
    edited June 2020
    Tom, you may not be doing anything wrong. Try this.


    This is how you can run an SFC scan in Windows.
    Be signed in to computer as Administrator.
    Press the Windows key + X to open the main menu.
    Click Windows PowerShell (Admin).
    When Command Prompt opens, enter sfc /scannow and press Enter. (Yes, there is a space between sfc and / ).

    The repair process will now start.  ( this takes a while but you have a percent counter to show progress.)

    Roy - W5TKZ
  • David Rolfe - VK3JL
    edited June 2020
    I was getting this as well.  Just formatted the PC and are starting the re-load Win10 again.
    I have the latest Realtek drivers for my PC and tried the Scan from Powershell.  I just gave up, figured it must be some other junk causing the issue.

    Only happened after upgrading to 3.1.12
  • Paul - K6HR
    Paul - K6HR Member ✭✭
    edited June 2020
    Open a support ticket. I'm sure Tim or Dudley will know what to do.
  • Marek Kamiński
    Marek Kamiński Member ✭✭
    edited June 2020
    I used to see the "pagefault..." BSOD often (Win 10 home) when I fought with topology of my Ethernet connections. I wanted the Flex <=> PC link on a separate Ethernet port, to avoid routing the radio related traffic through my home LAN. This brought a swag of problems with Windows Defender (unable to consider the separate link as private). When I tried bridging the LAN port with the Flex port in Windows, the system simply crashed. I had to connect the Flex (6300) with the PC through the LAN (i.e. to bring the whole traffic, radio related and unrelated, to the PC through one common cable) and the page faults disappeared.

    Marek SP5ISZ
  • David Rolfe - VK3JL
    edited June 2020
    Will do when I work it out, however fairly sure it's something to do with the Dax Microphone driver.  Maybe a New Windows 10 Privacy Issue?  I just removed it (with the utility) and it blue screened on install (at Step 24), so getting close.  

  • WX7Y
    WX7Y Member ✭✭✭
    edited June 2020
    By now this is a OLD issue  as I had it on one of my computers for the last couple years and the only fix that I found was a new Hard Drive and fresh format and a Windows 10 Pro re-install and start from scratch. 
    I was going to try Roy's suggestion on the old Hard Drive and see if that fixes the issue. 
    Here is one of the first reports to FLEX  https://community.flexradio.com/flexradio/topics/windows-10-update-vs-dax-new-problem-crash


  • Ted_Spiegel_NX6C
    Ted_Spiegel_NX6C Member ✭✭
    edited June 2020

    BSOD, Black Screen Of Death, is sometimes happening with Windows 10 feature update 2004. I had that problem and reverted to feature update 1909 and my stable system returned. 

    To revert I have found that Macrium Reflect images work much more reliably than using Microsoft Windows utilities.


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