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0xCAA70007

Microsoft 365 0xCAA70007 in Teams: connection interrupted at sign-in

Verified with sources4 sourcesReviewed Oct 3, 2026
Technician coming? See the 3 steps they must show you

Risk level

Medium

Proceed carefully and stop if the check is unclear.

Urgency

Medium

Quick answer

Teams or Office show 0xCAA70007 because the connection was interrupted during sign-in. Check you have internet; if the network works, IT should check whether a firewall or app blocks access.

Safety first

Stop and check this first

  • Microsoft warns that login.microsoftonline.com covers many IPs: a partial block can affect only some devices. A colleague's PC working does not rule out the network.

Safe checks you can perform

  • Internet connection
  • Sign-in test in the browser
  • Teams client update
  • Report the code to IT support

Leave these tasks to a qualified professional

  • Do not attempt this professional task: AAD Operational log and token processes
  • Do not attempt this professional task: Network assessment towards Microsoft 365
  • Do not attempt this professional task: Teams Sign-in diagnostic

What a technician must be able to justify

Technician visit

These are the steps they must carry out and show you. Tick them as they work: if steps are skipped, do not accept a part swap.

These are not instructions for opening or handling the equipment yourself. They are the checks that should support a technical conclusion.

  1. AAD Operational log and token processes

    What they doThe technician opens Event Viewer, Applications and Services Logs, Microsoft, Windows, AAD, Operational, and checks that firewall and antivirus do not block Microsoft.AAD.BrokerPlugin.exe or backgroundTaskHost.exe, and that the network does not block login.microsoftonline.com.

    They must show youthe error entries in the AAD log.

    In writingwhich process or destination was blocked and the exception applied.

  2. Network assessment towards Microsoft 365

    What they doThe IT technician uses Microsoft's network assessment tool and checks that firewall and proxy allow the Microsoft 365 URLs and IP ranges.

    They must show youthe assessment result.

    In writingthe blocked destination or port and the rule fixed.

  3. Teams Sign-in diagnostic

    What they doThe Microsoft 365 administrator runs the Teams Sign-in diagnostic in the admin center with the user's email, or the Teams Sign in test in the Microsoft Remote Connectivity Analyzer.

    They must show youthe test results.

    In writingthe issue found and the fix applied.

Before accepting a part or repair

Nothing has been shown yet. Do not accept a part swap based on the code alone.

Follow these steps

Note: Follow the documented order. An error code identifies the affected system, but it does not prove by itself which part has failed.

  1. Internet connection

    No special tools

    Who:
    you.
    How:
    open any website and check it loads.
    Result that matters:
    whether you have internet access when Teams fails.
    If there is no connection:
    fix the network first; the code comes from the missing connection.
    If there is:
    the block may be a firewall or another app; IT reviews it.
    Evidence to keep:
    time of the failure and network used.

    Evidence: Why am I having trouble signing in to Microsoft Teams?

  2. Sign-in test in the browser

    No special tools

    Who:
    you.
    How:
    open Microsoft Edge and go to https://login.microsoftonline.com; repeat in an InPrivate window and sign in. You should reach office.com or your company page.
    Result that matters:
    whether the browser reaches the landing page.
    If navigation fails:
    the block is in the network, local firewall or antivirus.
    If it works:
    the block affects the app; IT checks the token processes.
    Evidence to keep:
    screenshot of the Edge result.

    Evidence: Connection issues when signing in after updating to Office 2016 build 16.0.7967 on Windows 10

  3. Teams client update

    No special tools

    Who:
    you.
    How:
    in Teams, open the Settings and more menu next to your profile picture at the top right and select Check for updates. Install anything offered and sign in again.
    Result that matters:
    whether 0xCAA70007 goes away on the latest version.
    If you get in:
    the client was missing the latest update.
    If it repeats:
    go to the next check.
    Evidence to keep:
    Teams version before and after.

    Evidence: Fix Teams sign-in errors

  4. Report the code to IT support

    No special tools

    Who:
    you.
    How:
    note the status code at the bottom left of the window (0xCAA70007), the time and whether other Office apps fail too, and send it to your IT admin.
    Result that matters:
    IT getting the exact code.
    If IT finds the cause in the tenant or network:
    they fix it on their side.
    If not:
    IT opens a support request with Microsoft including debug logs.
    Evidence to keep:
    screenshot of the sign-in screen with the code.

    Evidence: Fix Teams sign-in errors · Why am I having trouble signing in to Microsoft Teams?

Still not solved

If the error persists, stop here. See what the technician must do and show you.

Where this code applies

A code is meaningful only inside the right product and version context.

Primary scope

System
Software and digital services
Brand
Microsoft 365
Product type
Office suites

Known code variants

  • CAA70007
  • Office 0xCAA70007
  • Teams 0xCAA70007

What it means

Microsoft describes 0xCAA70007 as a failed download because the connection was interrupted. In Office it appears with a message that one of the services needed to sign you in could not be reached, even when the network works. Microsoft says to check that the local firewall, antivirus and Windows Defender do not block the processes that get the token and that the network allows login.microsoftonline.com. The code does not tell a one-off drop from a block.

Warnings and stop conditions

  • Lowsource verified

    Microsoft warns that login.microsoftonline.com covers many IPs: a partial block can affect only some devices. A colleague's PC working does not rule out the network.

    Evidence: Connection issues when signing in after updating to Office 2016 build 16.0.7967 on Windows 10

Symptoms and causes

Probable causes · in order

  • One-off connection dropPossible

    Lost Wi-Fi or a PC waking from hibernation. Microsoft asks to rule this out before looking for blocks.

    Evidence: Connection issues when signing in after updating to Office 2016 build 16.0.7967 on Windows 10

  • Firewall, antivirus or network blocking sign-inPossible

    The network works but the failure repeats, sometimes only on some devices. It shows in the AAD Operational log.

    Evidence: Why am I having trouble signing in to Microsoft Teams? · Connection issues when signing in after updating to Office 2016 build 16.0.7967 on Windows 10

Virtual technician

Does 0xCAA70007 still appear after these checks?

Answer a few questions to narrow down the likely cause and the safest next action. Guidance only - it never replaces a professional.

Start diagnosis

Sources and technical references

  1. 1

    Fix Teams sign-in errors

    Microsoft · 2025 · official_doc

  2. 2

    Why am I having trouble signing in to Microsoft Teams?

    Microsoft · 2026 · official_doc

  3. 3

    Connection issues when signing in after updating to Office 2016 build 16.0.7967 on Windows 10

    Microsoft · 2025 · official_doc

  4. 4

    Microsoft 365 URLs and IP address ranges

    Microsoft · 2026 · official_doc

Sources: Fix Teams sign-in errors · Why am I having trouble signing in to Microsoft Teams? · Connection issues when signing in after updating to Office 2016 build 16.0.7967 on Windows 10 · Microsoft 365 URLs and IP address rangesreviewed 2026-10-03 · verified

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