If you're using Fluid Grids and want Design View back without rolling back, you can do the following...
Close all other files, open the Fluid Grid's css and add the X shown below:
/*
Dreamweaver Fluid Grid Properties
----------------------------------
dw-num-cols-mobile: X 4;
dw-num-cols-tablet: 8;
dw-num-cols-desktop: 12;
dw-gutter-percentage: 25;
=====================================
Then save and close the file.
Restart DW and you should have Design View from there on out on any files using that fluid grid .css file.