Announcements
Hi all, I’m looking for guidance on a recurring issue with Power Automate Desktop (PAD) automating Classic Outlook. The flow works reliably for a period (e.g., several runs across a day), but then starts failing again — usually the next morning / after a “cold start”.
In unattended runs, the flow sometimes fails at Launch Outlook with a COM exception. It can work fine for multiple runs (e.g., 6 successful runs across a day), then fails again later (often after overnight / first run of the day).
Cloud flow failure summary:
Action 'Run_a_flow_built_with_Power_Automate_for_desktop' failed: Problem while executing action 'Launch'. Failed to launch Outlook
PAD error details:
Run application
OUTLOOK.EXE /recycle
Launch Outlook
When I watched it in attended mode, I saw behaviour like:
This suggests a timing / cold-start / COM registration readiness issue rather than Outlook not being installed.
/recycle
taskkill /F /IM OUTLOOK.EXE
80080005 (CO_E_SERVER_EXEC_FAILURE)
OUTLOOK.EXE
Yes, this error often indicates that the Outlook COM server is not fully ready or accessible, even if the Outlook process is running. Common causes include:
Outlook profile not fully loaded or authenticated. Add-ins or startup processes delaying COM server readiness. Outlook running but in a hung or unstable state. Permissions or session context issues in unattended mode.
Note: Simply starting OUTLOOK.EXE does not guarantee the COM interface is ready for automation, which is why retries and waits are often necessary.
Yes. Microsoft and community best practices include (list is bit long):
Kill any existing Outlook processes before starting to avoid hung instances.
Start Outlook with the /recycle switch to reuse existing instances and reduce startup overhead.
Add explicit waits (5–10 seconds) after starting Outlook to allow full initialization.
Implement retry logic around the Launch Outlook action (e.g., 2–3 retries with delays).
Run PAD and Outlook under the same user context with proper permissions.
Avoid running flows when the VM session is locked or disconnected.
Disable unnecessary Outlook add-ins that may delay startup.
Keep Outlook and Office updated and repair installations if needed.
Use classic Outlook instead of New Outlook for better automation compatibility.
Referecen is here
Yes. It is a known pattern that after overnight idle periods or session recycling, the Outlook COM server may not initialize properly on first launch. The first run of the day or after a cold start often fails with COM exceptions due to profile loading, authentication, or COM registration delays.
Common impactful changes include:
Using /recycle switch when launching Outlook.
Implementing robust retry and wait logic around Launch Outlook.
Ensuring PAD runtime and Outlook run under the same user account with proper permissions.
Disabling unnecessary or problematic Outlook add-ins.
Configuring Outlook in Cached Exchange Mode to improve profile load times.
Keeping Outlook and Office fully patched and repaired.
Avoiding locked or disconnected VM sessions during unattended runs.
Using classic Outlook instead of New Outlook for better automation compatibility.
Creating warm-up flows that launch Outlook early in the day to avoid cold start issues.
Under review
Thank you for your reply! To ensure a great experience for everyone, your content is awaiting approval by our Community Managers. Please check back later.
Jump in, show your community spirit, and win prizes!
Expanding mentorship, skilling, and AI innovation
These are the community rock stars!
Stay up to date on forum activity by subscribing.
Valantis 377
11manish 279
David_MA 234 Super User 2026 Season 1
