Fix is on the way. This issue is to document the problem, which was reported privately, so that others can see the solution.

The problem is with serializing and deserializing device handles as they are passed through the named pipe between NpcapHelper.exe and the calling process that loaded Packet.dll. For 32-bit processes like Nmap, serializing this as 8 hex digits (4 bytes) works, but for 64-bit processes this missed the upper portion of the address. We will switch to using the "%p" format specifier, which works consistently regardless of the architecture.