If you are trying to sign in to Microsoft Teams and you see a message "We're sorry—we've run into an issue." If you look at the bottom left of the screen you will details of the error Error code - caa70004 then the reason for the error is that the server or proxy was not found.
Why the Error - caa70004
There are two main reasons that can cause this error - Misconfigured Proxy or when using Network Sniffing Programs.
Misconfigured Proxy:
If you have misconfigured a proxy server on your Windows/macOS device, it can prevent Microsoft Teams from connecting to its server this causing this error.
It could be so that you have configured the proxy server correctly it is not reachable, which can also lead to a caa70004 error.
If Using a Network Sniffing Program:
This often happens to me, when trying to test something using a Network Sniffing tool like Fiddler being configured to decrypt HTTPS traffic, this intercepts network traffic causing other applications like Microsoft Outlook and Teams to not work.
Fix:
Make sure that your proxy settings are set correctly. If you are unaware of how it is done, it is better to reach out to your organization's IT admin.
Secondly, if you are using a network sniffing tool, make sure it is configured correctly, or turn it off to make teams work again.

Facing issues? Have Questions? Post them here! I am happy to answer!
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