Resolution not changing

Hopefully this is in the right forum section but when I open WoW it's got two black vertical bars at either side of the screen, when i go into the settings I try to change the resolution to 1366x768(Wide) to match my laptop's resolution, I click apply, however the resolution just seems to stay completely the same even though it says 1366x768 in the settings. Any suggestions on fixes would be appriciated!

Having the same issue, tried changing both to a wide (2560x1440) and non-wide (1920x1440) resolution to no avail. Any suggestions?

Have the exact same problem!

Make sure your folder is not set to read only.