The Teams clients use HTTPS to communicate with the O365 cloud. Mainly for administration, user status (presence and notifications) and other messages for the O365 reporting for the admins.
You all know how to get the Teams logs right? It’s here if you forgot how.
How to get this data then? Well, I’ve been shown two main ways of collecting this data (and I do use them).
Using the Fiddler desktop client
Firstly, using the Teams desktop windows client. Usually, I use the Fiddler HTTPS capture tool. You can download the classic version from here.
To get all the data that you need to have a look at troubleshooting the traffic, you will need to enable HTTPS decryption. Let me just halt here and say this:
This method will allow you to see all data unencrypted, from the client that you install fiddler on.
So, please do be careful with this. It only logs and decrypts on the client that you have installed Fiddler on.
With that warning behind us, use these steps to turn on the HTTPS decryption on the Fiddler client:
- Open Fiddler.
- Go to Tools => Options; then go to the HTTPS tab.
- Enable Capture HTTPS CONNECTs and Decrypt HTTPS traffic:
4. Click on OK.
5. Then acknowledge all the warnings.
That will start logging the traffic from the Teams desktop windows client. There will be traffic like this:
You can click on each of the items and see the REQUEST and RESPONSE. There will be plain text there. Usually, it will be in the JSON format. There is a tab in the headers in the window view of the Fiddler client, which will let you choose the view.
Another factor here, make sure that the Teams desktop client cache has been cleared.
- Close Teams.
- Delete the contents of this folder %appdata%\Microsoft\Teams
- Open Teams again and sign in.
- Reproduce the issue.
Ok, how about if the Fiddler client can’t be installed?
There are two options in this situation:
- Install a lightweight version of Fiddler https://www.telerik.com/fiddler/fiddlercap.
- Use the Chrome / Edge browser to capture the network trace.
Using Chrome / Edge
Ok, now this option produces “Fiddler” like traces from a browser version of the Teams client.
Easy to do really, just open the Google Chrome client:
- Open a Private Browser session.
- Press F12.
- Click on the “Network” tab.
- Make sure the “Preserve log” tick box is ticked.
- Reproduce the issue.
- Then right click on the messages in the dialog box and select “Save all as HAR with content”.
The log can be opened in Fiddler or in Charles web debug proxy (which organises the traffic in a slightly unique way).
As for separate ways, the logs from the Chrome / Edge method (the HAR), is slightly different. I personally go for a fiddler trace from the windows client, with the Teams logs.
