HVR cameras get yellow x's unexpectedly

Symptom

A yellow "X" appears on the hardware tree in Alarm Monitoring for the HVR, but the unit is still online.
The unit was working and now does not. The camera type in System Administration is blank, and the Lenel DS4016HCI is not shown in the "Camera Type" list.
 
After checking update capabilities works, an hour glass appears for 10 sec, and then disappears. A download causes a driver error in the panel download.
Device Manager does not show the DS4016HCI in Sound, video and game controllers.

Resolution

Either reseat the capture card, or remove and clean the card's contacts with pencil eraser, or replace the capture card.
The capture card has failed, which affects the LNVR operation. As a result, the LNVR appears online and normal, but all the cameras are not online.

Applies To

Hybrid Recorder
LNVR (All versions)
LNVR 6.4.500
OnGuard (All versions) 

Additional Information