Follow the solution here, which also solves Kuler in photoshop cs6 not working.
Photoshop CS6 Extended Mini Bridge Not Working
Specifically these are the instructions:
https://blog.igment.com/2017/11/01/photoshop-empty-mini-bridge-panel-bug/
While adobe provided an actual fix for a similar problem with the Bridge CS6 output panel, sadly adobe has not done the same for photoshop cs6 in regards to the Kuler and Mini bridge panels, thusly that's the reason for the above fix.
After both Kuler and Mini Bridge should work in photoshop cs6.
