First of all close the wallet application.

Then...

you have to go to application data... to fix it...

One of the ways to access it is by pressing "Windows" key on your keyboard with "R" that will bring up the Run command. Type in "%appdata%" then enter...

Bitcoinz folder and you should see file called bitcoinz.conf > Open it and use notepad to open the file

Paste this into it

addnode=62.12.7.151
addnode=[2604:a880:cad:d0::5e39:4001]
addnode=[2a01:4f8:c0c:3532::2]
addnode=[2a02:c207:2013:2448::1]
addnode=107.181.174.211
addnode=62.12.7.151
addnode=btcz.webrats.com
addnode=btcz.owlminingclub.com

save it and re-open your wallet

enjoy!