Avatar of msidnam
Flag for United States of America asked on

Error Code OX800704cf when accessing some UNC paths

We are having an issue when accessing certain UNC paths. We are getting an 

Error Code OX800704cf. We have Windows 2019 servers and we have a policy where the desktop, video, downloads, pictures and documents get redirected to a file share on another windows 2019 server. 

when this error happens most UNC paths do not work but i can ping the ip and server name. the only unc paths that work is a path to one of our netapp filers (one works and another netapp we doesnt work for unc) and an overland storage device. 

I'm wondering if its because of a windows update but since this happens randomly we just noticed this christmas week and we had updated a couple times. 

We are using VMWare 6.7 and I noticed we were using e1000e NIC and changed to VMXNET3 but still having the issue. 

If anyone has any ideas please let me know.

Thank you.

Windows OSWindows NetworkingVMware

Avatar of undefined
Last Comment

8/22/2022 - Mon
David Johnson, CD

try the same using the command prompt. it is a connection error not authorized.  you may  have to connect to the server using net use and enter the login details

If i try net use command it says system error 67 has occured. the network name cannot be found. However I can ping the servername.

By chance, On one of the servers having the issue I had a snapshot from before the updates. I reverted back to the snapshot and have rebooted several times with no errors. I'm just not sure what update. It might be kb5008218 but I am not sure.

Edit: Nope, wasn't KB5008218. At a loss now.

I want to try and restart services when this happens to see if its a specific service but I can't seem to find what service(s) control UNC.
Experts Exchange is like having an extremely knowledgeable team sitting and waiting for your call. Couldn't do my job half as well as I do without it!
James Murphy

Not sure if this helps, but when this happens it seems like it can connect to things that are using SMB 1.0 but not SMB 2.0 or above which is odd because shouldn't 2019 speak SMB 2.0 natively? the share its supposed to connect to is another windows 2019 server with, im assuming, SMB 2.0.

When the UNC path doesn't work, I found out if I restart the workstation service it works again even without restarting the whole server. Now to find out why the workstation service has issues every X amount of reboots.

e1000 should only be used at an initial state for OS deployments and not in production environments. Remember to have the VMware Tools installed so Windows can recognize the NIC vmxnet3.
Try out a week of full access for free.
Find out why thousands trust the EE community with their toughest problems.

Thank you. I did change the e1000 to vmxnet3 a couple weekends ago but it didnt fix the issue. We did notice our backup server was saturating the network and causing some congestion. We also added a script that if it couldn't connect to the UNC path to reboot. We will probably remove that soon to see if it works now that we throttled the backup server.

View this solution by signing up for a free trial.
Members can start a 7-Day free trial and enjoy unlimited access to the platform.
See Pricing Options
Start Free Trial
Ask your own question & get feedback from real experts
Find out why thousands trust the EE community with their toughest problems.