11 Replies Latest reply on Jun 9, 2020 9:22 AM by VDINinja311

    Writable Volumes not allowing USB redirection

    HastingsCounty Lurker

      Seeing if anyone has a solution to this while I wait for support to finally respond.


      On Horizon 9.7, App Volumes 2.18, UEM, 9.8

      Have two pools, Windows 7 32-bit, and Windows 10 LTSC 64-bit.

      Writable Volumes enabled for UIA plus profile template.


      We had an issue last week, which I think is the result of this. Our Sophos appliance seemed to lock up, causing all our VDI connections to be refused from the thin clients. After shutting down the appliance, staff were able to login again and everything seemed fine. Couple days later I we start getting tickets about USB sticks not working. Certain users were not able to use USB devices. I'd login to the same thin client, and it would work.

      Tried removing the Sophos client from the golden image and keeping the appliance off and USB still did not work. After testing more, my profile became intermittent with USB devices too. If I logged in, USB would not work. If I disconnected the session without logging out, and then reconnect USB would be functional until next log off. Both pools were effected by this and it's random users.

      After deleting my writable volume and allowing it to be re-created I have had no issues. Any user I move from Windows 7 to Windows 10, creating a new writable volume is having no issue. Looking for a fix without having to delete their writable volume.

        • 1. Re: Writable Volumes not allowing USB redirection
          ijdemes Expert

          Do you mean the issue that results in USB redirection not being available? If so, you can use the key/value below (default timeout is 60 seconds). You can extend to (for instance) 200 seconds.


          Use the existing or create new reg sub key:


          HKLM\Software\VMware, Inc.\VMware VDM\USB


          Create a REG_DWORD:




          Give it a decimal value of 200 (for 200 seconds), REMARK: This should be a value that falls within your "normal" logon times.


          Make sure above is part of the golden image and a reboot has been performed.


          This should fix the USB redirection not being available issue.



          • 2. Re: Writable Volumes not allowing USB redirection
            HastingsCounty Lurker

            thanks for the suggestion. I looked for the regkey and do not even have USB as an option in my golden image. Wondering if I should add it;

            • 3. Re: Writable Volumes not allowing USB redirection
              HastingsCounty Lurker

              Disregard, didn't read the part to create the USB subkey. Will apply and test. Thank-you.

              • 4. Re: Writable Volumes not allowing USB redirection
                HastingsCounty Lurker

                Tested and does not appear to resolve the issue. Waited a few minutes after login to see if USB would function, no change.

                • 5. Re: Writable Volumes not allowing USB redirection
                  ijdemes Expert

                  Hmm, did you make sure it was part of the golden image before cloning?

                  • 6. Re: Writable Volumes not allowing USB redirection
                    HastingsCounty Lurker

                    Yup, I made sure it was their after logging in and I see the key. I have tried uninstalling the agent, removing the vmware certs and re-installing the agent. Same thing. If I disable the users writable volume, USB is fine.

                    • 7. Re: Writable Volumes not allowing USB redirection
                      robsisk1972 Enthusiast

                      So I believe I have the same issue but it doesn't involve writable disks.   Mine revolves around users with more then 3 or 4 app stacks assigned by App Volumes.   If no App Volumes are assigned USB redirection works as desired.   I believe the length of time it takes to attach these volumes is exceeding 60 seconds.   Will crack my master and change the value to 200.   This makes a lot of sense to me.   Will report back with the verdict in my case.

                      • 8. Re: Writable Volumes not allowing USB redirection
                        sujayg15 Enthusiast
                        VMware Employees

                        Just checking if we've eliminated and GPOs / security policies that could be blocking USB storage media. I've seen one instance where this happened, where someone else created and applied a regular GPO that blocked USB Storage. Another instance where Horizon GPOs were involved (link). And a 3rd where Horizon Smart Policies were in play blocking USB (link).

                        • 9. Re: Writable Volumes not allowing USB redirection
                          bjartest Novice

                          We also see the same behaviour that USB redirection is not working. We use appvolumes (with writable) and DEM. DEM smart policy is enabled with AD group to allow USB redirection but this setting is completely ignored. What we did find out that worked was to add this setting to the registry and USB started working again. You can try this on a session and just disconnect/reconnect to se if it works.


                          Add the following registry setting:

                          REG_DWORD registry value UemFlags in key HKLM\Software\VMware, Inc.\VMware VDM\Agent\USB, and setting it to 1.

                          • 10. Re: Writable Volumes not allowing USB redirection
                            VMVSF Lurker

                            I actually ran into this issue myself.

                            This occurred after we upgraded our Instant Clone VDI image from Windows 10 1809 to 1909.


                            We made sure to use the latest versions of Horizon Agent 7.12, DEM 9.11 and App Volumes 2.18.4 (haven't moved to 4.xx yet)


                            I couldn't figure out why USB redirection was working on my login but almost never on most other users.


                            I had to rollback to the 1809 instant clone image and then it worked fine.


                            I tried downgrading the Horizon Agent and DEM on the 1909 image, but still kept getting the "[ws_vhub] vhublib: Check [UemState]->[DONE] timeout" in the logs.


                            It finally clicked when I realized I didn't have a writable volume (I purposefully disabled mine a while ago).  When we disabled the writable on another user, USB redirection worked again on the 1909 image.


                            Also, when deleting the writable and letting it be recreated, USB redirection worked again as well on the 1909 image...


                            So, apparently upgrading Windows 10 versions without nuking your writable volumes will also cause USB redirection to fail.


                            We worked around this, for now, by setting the UemFlags key to 257 decimal in the registry.  (Placed in "HKLM\Software\VMware, Inc.\VMware VDM\Agent\USB" through a GPO)


                            Hope there comes a real fix for this issue in the future instead of disabling Horizon Smart Policies. (We didn't use them anyway.)

                            • 11. Re: Writable Volumes not allowing USB redirection
                              VDINinja311 Enthusiast

                              Has anyone opened a VMware case regarding the writable volume causing issues with USB redirection?