When you feed an envelope, you get a blank impression.
Cause
An internal expiry timer is reached when postage funds are not refilled in the meter for over one year (365 days). An envelope feeds without printing and the meter does not dispense funds.
Resolution
You must add postage to your meter to resolve this error code. While the meter is not out of postage, it requires a minimum of $1 to be refilled to the meter.