Late, but I'm actually glad you talked not turning of your antivirus , to get itch to work. Because that's the main thing Google recommends you to do
And sure, if you're using some obscure antivirus, then maybe that'll help? But if you're using a common one, or the one that comes built in. Then don't, unless you tried absolutely everything else
And what worked for me, was simply opening the app, then closing it from Task Manager (honestly not sure why, but it worked)