FAQ: Why Does My HP OfficeJet 5100 Error When Scanning?

We have found that the WIA driver for this device returns an invalid pending count.

Our twain components ask the driver for the number of pending pages waiting to be scanned after each acquisition. If there are no more pages, but the driver returns a value indicating there are more to scan, an exception may be thrown.

You should contact HP to see if there is an updated driver for the device.

Original Article:

Q10038 - FAQ: Why Does My HP OfficeJet 5100 Error When Scanning?