Cannot start "VMware DHCP Service" after upgrading to VMware Workstation Pro 25H2u1

[Sylvain Langlois]

Hello,

We've started rolling out VMware Workstation Pro 25H2u1 across our environment (upgrading from 25H2), and have run into a few reports of NAT networking no longer functioning after the upgrade.

After some troubleshooting, we found that the "VMware DHCP Service" fails to start, returning an error. This appears to be the root cause of the NAT issue.

Performing a full uninstall and reinstall of 25H2u1 resolves the problem on affected machines.

Has anyone else experienced this behavior with 25H2u1? Any insights into the cause or a more targeted fix would be appreciated.

Regards,

Syl

-------------------------------------------

[RaSystemlord]

I have no inside information on this, but generally speaking about Windows ...

Uninstall of the new version - cannot see how that is the culprit. But a proper uninstall of the previous version, is probably the issue. Uninstall is just another program (of the old version), which can fail OR perhaps it is not even supposed to work if you did not reboot. I mean, the OLD service might be hanging around (in registry or somewhere) after running the uninstall, while a reboot will only get rid of it ... and only after that the install of the new version is successful.

You also mentioned a concept of "full uninstall", which can mean many things - running a cleaner software, reboot, removing manually entries from registry, a second reboot, removing files under program files ... and that sort of things, not necessarily in the order I wrote them. Not sure what you did.

Sometimes, things like these happen. The fix is not to the new version, but an Utility, which will clean up the system ... like I said in the beginning, I don't have any inside information on the software.

[Ian Forbes]

Which host OS?

-------------------------------------------

[Sylvain Langlois]

Hello,

Windows 11.  The one that I am aware of were 25H2 but we've got a mix of 23H2 and 25H2.

Regards,

Syl

-------------------------------------------

[Dhairya Tomar]

Sylvain Langlois Requesting you to upgrade to the latest version of WS 26H1 and update if the issue still persists.

-------------------------------------------

[Sylvain Langlois]

-------------------------------------------

[Sylvain Langlois]

Sorry, I completely misunderstood.  When I will have some time, I will package the latest version and report back if the problem is still present.

[Derek Logie]

Such a failure can be caused by an error in the config file which is (typically) C:\ProgramData\VMware\vmnetdhcp.conf  .

Are you adding host entries so when using DHCP you get the same ip address assigned ? Try comparing it with an older version if you can.

The reason a de-install/re-install fixes this is because it will re-create the config file.

------------------------------
Derek ...
------------------------------

[Sylvain Langlois]

I had another case this morning.  I compared the "non-working" vmnetdhcp.conf to the newer vmnetdhcp.conf after uninstall / reinstall.  It was basically identical.  The user did not add anything to his config.  The service did not start correctly before uninstalling and it worked fine after the uninstall / reinstall operation (with a reboot between the uninstall and reinstall).

-------------------------------------------

[RaSystemlord]

The exact problem, when there is a need to install a program creating a service, twice, uninstall and reboot, in between, is not unheard of in Windows. I had that same thing for years with some professional software (through many versions of it). Never tried to find out why that was - because it was very quick to do - but I think there was something wrong in the install procedure. This was about a clean system. In think that on Windows Server OS, install worked correctly.

Not sure how this helps, but I would study the install procedure after these latest confirmations - maybe a too aggressive time-out somewhere. Event Viewer might tell something.