I am having this issues since I moved my installation from MAMP to my host. Before you suggest it, this has nothing to do with MAMP. I am running the latest version of WordPress (4.6.1).
NOTES:
– Not only does it not save anything but the “Visual” and “Text” tabs aren’t available.
– I have “Disable the visual editor when writing” unchecked
– Change Memory Limit plugin installed and increased to 256
– Accessing the widgets from the Appearance > Widgets screen does not help
– All Optimizer widgets are enabled
– My Optimizer license is activated