When the reflector sends a critical request to the driver host process, the host starts an internal timer. The default timeout interval is 60 seconds. Critical requests include Plug and Play, power, and I/O cancellation.
As long as the User-Mode Driver Framework (UMDF) driver performs operations on a regular basis toward completing the request, the reflector extends the timeout period. For example, for a remove request, the driver needs to return from the remove callbacks at regular intervals.
If the timeout period expires, the reflector generates a WER error report, terminates the host process, and attempts to restart the device. For info about automatic restart, see Using Device Pooling in UMDF Drivers.
For info about the fields in this report, see Accessing UMDF Metadata in WER Reports.
Timeout expiration is the most common reason for the reflector to terminate the host process.
You can extend the timeout period by using the WDF Verifier Control Application.