Take a look at this topic. A lot of peeps have this issue.
Just open bnet app
The go to your wow installation folder
Logs folder
Right click hotfix and tooltip, then properties
Put both files to read only, apply and ok.
Launch the game
But after you exit the game the bnet app will update the game reverting this, meaning you will have to do this everytime u want to play again…
A solution to thia is loading wow from wow.exe inside wow folder
Ps: retail folder