When building programs in the Windows build that use mongoclient.lib, events happen in this order:
1) A new mongoclient.lib is built;
2) Example programs are built using the previous day's mongoclient.lib;
3) The new mongoclient.lib is copied to the root of the built tree so it can be used for tomorrow's build.

This falls down any time an interface is changed such that a new function signature needed is not found in the previous day's version of mongoclient.lib.

We could either not copy the mongoclient.lib to the root of the build tree, or copy it before we link the client example programs, or force the linker to use the full path to the version of mongoclient.lib that was built from today's code.