WP 3.9.1 CONNECTION LOST?!!! HELP!

Since downloading the latest version of WP 3.9.1, I TOO have experienced a CONNECTION LOST error when adding new and/or editing Pages and Posts!

I am using Yahoo Site Builder, seriously hating that I updated to 3.9.1 as I am now 3 weeks behind on progress. Can’t seem to find much assistance with this problem!

All advice is appreciated!