If you use FatMoon, Starter, Agency, or Rife theme then there is a chance that customizer will not allow you to save changes when you have Redux Framwork plugin in version 3.6.4.
In that case download attached Redux 220.127.116.11 and install it in your WordPress.
I had to pack it and attach it here cause I couldn't find such package anywhere else to be ready for download.
This is temporary solution until Redux will release another official release, or we we will remove dependency for Redux framework from our theme.
Sorry for problems! It was not in our control.
With kind regards.
Post edited by Air on