HTML5 vSphere Web Client error message

Hi, we are running version 6.7.0 across the board and just today we are able to connect in using the VSphere Web Client (Flex), but not HTML5.

Error produced:
503 Service Unavailable (Failed to connect to endpoint: [class Vmacore::Http::LocalServiceSpec:0x0000004fa48f0390] _serverNamespace = /ui action = Allow _port = 5090)

When we log into the Flash enabled client, the options to restart the VMware vSphere Web Client are greyed out, even when logged in as local admin (see attached).
This article suggests changing the web client timeout, but I am reluctant to do that as it was working fine before.
https://communities.vmware.com/thread/566078

Is that what needs to be done here, and if so, where is the webclient.properties file on a Windows Server 2012 R2 box running vCenter?

Any help would be mich appreciated. Thanks.
7-9-2019-2-49-34-PM.png
Kevin MSystems EngineerAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization ConsultantCommented:
As for the issue, Restarting Network Management services or host restart and check if you still have the same issue.

see here for the documentation to change it

https://kb.vmware.com/s/article/2040626

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Kevin MSystems EngineerAuthor Commented:
Thanks,  we were having difficulties finding that file on the 2012 server. I found it, but getting Access denied when changing the session.timeout value, which was commented out.

That being said, I restarted the service using the followingL
C:\Program Files\VMware\vCenter Server\bin\service-control --stop vsphere-ui
C:\Program Files\VMware\vCenter Server\bin\service-control --start vsphere-ui

After thinking about it for a minute the HTML5 client is back up.
Thanks for your quick response, and I'll still look to change that value.
Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization ConsultantCommented:
Make sure you are a local administrator, services are stopped, and using a Administrative command prompt.
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
HTML

From novice to tech pro — start learning today.