The following describes a circumstance where a ShadowLink patient, associate, or document delivery is in a pending status long after being received.  You may witness the job in a status such as this on the management screen:

From there to further diagnose the problem, attempt to download the job by clicking on the blue icon on the left of the row:

If you witness this error, the job is in a pending status because the file had no contents at the time of upload: