Can you check your settings and click Auto Detect Paths
Ensure the paths are correct:
- Retail = {Your Drive}
{Your Path}World of Warcraft_retail_ - TBC = {Your Drive}{Your Path}World of Warcraft_classic_
- Classic Era = {Your Drive}{Your Path}World of Warcraft_classic_era_
- World of Warcraft launcher Path = {Your Drive}{Your Path}World of WarcraftWorld of Warcraft Launcher.exe
So, for me, since I am using a 4tb PCIe 4.0 SSD NVMe drive, my path would be H:World of Warcraft_retail_
Once you sorted the location, within settings ensure that your username and password is correctly entered in their appropriate fields, then click on Okay button and see the account info. Finally try the Reinstall button.