Network error while connecting to HTTPS endpoint from MS office word add-in (After August 13th windows update)

Question

Hi guys,

I've been developing word add-in and side-loading it. It was working fine until the new windows update windows-10-update-kb4512508. After this update every time my add-in tries to connect to secure(https) endpoint, it throws network error. Usually it used to work after I trust my self signed certificate, but now it's not working even by doing that. I think that it has something to do with the windows update, as this update included some security enhancements to internet explorer, edge, networking technologies etc..

Is there anyone else facing the same issue as I am? Any ideas on how to fix it? or any work around for this?

I've gone through all the documentation from microsoft and the links to these documentations are-

https://docs.microsoft.com/en-us/office/dev/add-ins/concepts/requirements-for-running-office-add-ins

https://docs.microsoft.com/en-us/office/dev/add-ins/testing/create-a-network-shared-folder-catalog-for-task-pane-and-content-add-ins

https://docs.microsoft.com/en-us/office/dev/add-ins/testing/debug-add-ins-using-f12-developer-tools-on-windows-10

Additional Information:

Below is the information of the system-

Windows 10 Home:

      Version - 1903

      OS Build - 18362.295

MS Office 365 MSO:

      Version - 16.0.11901.20204 (64 bit)

Edge:

      Edge Version : 44.18362.267.0

      Edge HTML : 18.1832

Additional Info:

I downgraded my windows to try an d narrow down the the issue I'm facing is because of the latest windows update. The windows version info after downgrading is-

 Windows 10 :

      Version - 1809

      OS Build - 17763.678

After downgrading, my add-in is working as usual. It was able to connect to the https-endpoint(cross-domain) without getting any network errors. So I feel something that was introduced in the latest window update is  restricting my adding to connect to the https-endpoint(cross-domain). It would be helpful if someone can help me out with this.

Note: Basically I'm doing a cross domain call. Through internet explorer and edge browser it is working fine as expected before and after downgrading the windows.

Answer 1

I downgraded my windows to try an d narrow down the the issue I'm facing is because of the latest windows update. The windows version info after downgrading is-

Windows 10 :

  Version - 1809

  OS Build - 17763.678

After downgrading, my add-in is working as usual. It was able to connect to the https-endpoint(cross-domain) without getting any network errors. So I feel something that was introduced in the latest window update is restricting my adding to connect to the https-endpoint(cross-domain).

Answer 2

Hi Antoneth,

Thank you for the reply. I have raised a question in Microsoft developer network. It's been like 4 days since I've raised it, but, no replies yet. Below is the link to that-

https://social.msdn.microsoft.com/Forums/en-US/4057b5a4-c0ad-45f8-985d-0ec54b41f07c/network-error-while-connecting-to-https-endpoint-from-ms-office-word-addin-after-august-13th?forum=worddev

Answer 3

Hello Paul, 

Regarding your concern related error while connecting to HTTPS endpoint from MS office word add-in, it is best to post your question in **Microsoft Development Network (MSDN) forums**where you can get advanced and technical answers from the most qualified pool of respondents, and other partners who can respond to your query appropriately.

They can either share their knowledge or learn from your interaction with us.

Should you have any other concerns, don’t hesitate to let us know.