Outlook Disconnection Over ZApp

Hi David,
Indeed i raised a case: 646045. We do have this option enabled: Restart WinHTTP Service. I’ll try turning this OFF and will check.
Hope this will not make issues or downtime as it’s live in production.

Just to add, the below is our current setup.
Forwarding Profile:

  • Tunnel with local proxy
  • A custom pac file.

App Profile:

  • Added a custom pac file.
    Install SSL Cert: Checked
    Disable Loopback Restriction: Checked
    Override WPAD: Checked
    Restart WinHTTP service: Checked

Did turning off Restart WinHTTP Service solve your dissonnect with outlook, thick client?

how did you solve this please?

Hi David,

Even to one of our customer facing same issue.
Case number : 982251

“Restart WinHTTP Service” is in OFF, using Tunnel with local proxy.

Can you please help me here.


Hi Atul,

Even to one of our customer facing same issue.

“Restart WinHTTP Service” is in OFF, using Tunnel with local proxy.

Can you please let me know is the issue is resolved ? If yes then what is the solution.

Hi all

We have the same issue now.
Is there any solution for this topic?

BR Daniel

are you using tunnel with local proxy mode?
try adding explicit statement in proxy pac file to send login.microsoftonline.com to zscaler IP or $gateway.

Hello community,

I am Georgios. Recently, we deployed ZPA in my company and this is still on POV (proof of value) phase. We are receiving complains from users having the same exactly issue. Frequent disconnects from Outlook and skype.

Is there any formal solution that has been proposed from a zscaler engineer as a fix for that?

That is happening to both macOS and windows machines. There is no difference while it is on tunnel or tunnel with local proxy.

I am not convinced that it is a configuration problem or it is simply a zscaler problem.

Thank you in advance,

Hi Everyone,

There’s a few issues that we’ve seen over time that can cause the same symptoms.
What would really help us is if you can list some particulars, most importantly which Z App you are running. If you’ve got a ticket open please paste the number in here and we can check that also.

Troubleshooting these issues usually requires logs and a lot of your specific data, so it’s generally better for these issues to go through support.



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Hello David,
I hope you are doing well. We are also facing the issue by few users in few Brands.
Ticket #1010449
Many thanks,

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Hello David,
Please find hereafter another ticket, regarding the same topic.
Best regards,

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Ticket numbers-1011292, 1007469

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Hi David ,

  • Request #1016063 is the case number which we have opened for the same .

This issue is random and doesnt happen for all users . We are using version app . Forwarding method is tunnel over pac . Please let me know if we have any solution for this .

We are also suffering from Outlook disconnecting randomly. Doesn’t seem to happen for all users but certainly the majority.

App version is and tunneling with filter driver.

We are raising a call with ZScaler today, will post the request number later.

Hello people,
Have you been able to fix this issue ?
We also have a case opened with Zscaler support since months but still no luck.
Thanks for any input.

We have seen this a several customer over the last few months, what thing we note is we say this more now with ztunnel 2.0 than previous

One solution we found was to switch from tunnel with local proxy to a packet based deployment of ZAPP

Thanks Alex, we are still on Zapp 1.5.x, not 2.0 yet.
By “packet based deployment” you mean Tunnel mode (without local proxy) ?

Yes apologies tunnel mode, with packet based filtering

We are having similar issues and we are trying to use ZIA when the user is connected to our traditional VPN solution in order to offload Internet traffic from the VPN
In such cases Zscaler is recommending Tunnel with Local Proxy (https://help.zscaler.com/z-app/best-practices-zscaler-app-and-vpn-client-interoperability) and in this mode we are getting hit by these disconnect issues without any solution from support yet
Even trying just Tunnel mode we get even worst issues with Connection Errors in ZApp for ZIA
We are using the 1.5 version still

We also having similar issues. For some users Outlook does not connect, or for whatever reason it have message “password needed” but nothing happens more. Issues started when we enabled modern authentication in our o365 tenant. Issue is mainly when users are outside our network, when Zapp is creating local proxy (tunel with local proxy). When we enabled packet filter based settings, it was better, but problem was that then traffic was skipping proxy, and as for MFA we are consider Zscaler IP as trusted, we had MFA popup for users, so this is not solution for us.