Ok i am probably going to get smacked by the mod for replying to this because there are several Like it .
But i have suggested a few things like clicking on the cogwheel next to the play button and going in to settings / game settings and making sure the launch location folder is pointing to C/ windows/ programs / world of warcraft.
Also check that there isn’t a small green arrow next to your Battle. net Icon for you to update it ( because mine updated twice this week)
If all of this fails , delete the Battle.net program and use you browser to open you account and download a new one.
The download link is at the top of the page now.
But i bet its the folder pointing thing cause that got me a couple of times when I had a big patch.
I know its frustrating not getting a reply,
And another bug that happens is sometimes the world of warcraft folder permissions switch from ’ read and write" to " read only" make sure it says " read and write"
And another bug that can happen ( might as well mention all of them I know) is the desktop icon can become corrupted. try opening battle.net from the program in the Wow folder directly.
please let me know if anything helped,
of course this is all contingent if you have already added the exceptions to your antivirus and it still doesn’t work