I can tell you what worked for me...

1) Open the "%appdata%\huntercoin" folder. (The "datadir" or data directory.)

2) *** BACK UP YOUR WALLET.DAT AND HUNTERCOIN.CONF FILES *** (see my sig for a wallet.dat backup utility) DO NOT DELETE YOUR WALLET!

3) Move all files except for wallet.dat and huntercoin.conf to another folder. You can delete these files after you have completed all the steps here.

4) Ensure that you have the "addnode" entries in your huntercoin.conf file that are in the OP.

5) Start huntercoin-qt.exe. It will download the blockchain entirely from scratch.

6) Once the blockchain has finished downloading, you can then safely delete the files you moved in step 3.

That has worked for me on 3 different machines.

I tried the "-rescan" option several times on 2 machines -- no luck. It didn't work. It has worked in the past, but not for the kinds of errors that we're seeing now.