HI
@Nanda_Duddala,
The error {"status":400,"message":"Invalid request","source":"api.connectorP.svc.ms"} points to an access failure, not a logic problem in the flow. It ran fine before March 5 at 09:00 AM PST. When a stable flow stops at a specific time, the cause is almost always external.
Check how the OneDrive step connects
Open the flow. Go to the "List files in folder" step that failed. Check which connection it uses. If the connection owner had a password reset, re-enrolled MFA, lost a license, or got deactivated, things stop without warning. Fix this error by signing in again using your credentials or a service account with active access.
Check if the OneDrive connector was updated
Early March saw backend changes to api.connectorP.svc.ms paths. Flows started failing together at the same time, which lines up with what you are seeing. Check the Power Platform admin center for recent connector changes. The M365 service health dashboard may also show incidents tied to OneDrive or Power Automate around that window.
Reconnect the OneDrive account
Go to Power Automate. Open Data, then Connections. Find the OneDrive for Business connection tied to these flows. Delete it and create a new one. Update every affected flow to use the new connection. This clears most 400 Invalid request errors caused by expired OAuth tokens.
Verify the target OneDrive path
A 400 error on "List files in folder" also appears when the folder path no longer exists or the path string has a formatting issue. Confirm the folder location still exists and the path inside the step is accurate.
If all flows stopped at exactly 09:00 AM (this happened to me in the past)
That precision points to something scheduled. This could be a scheduled policy rollout, a credential expiry, or a maintenance task that is scheduled to run overnight between March 4 and 5. Ask your tenant admin what changed during that window.
Start with reconnecting the OneDrive connection. That resolves 400 Invalid request errors from api.connectorP.svc.ms in most cases.
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