Piwik 2.0 now uses Less for compiling CSS (which helps write smaller and more maintanable CSS) and so the CSS file now requires the merging unfortunately.
I guess the problem is the css file cannot generate because of timeout error, or other.
When you enable the CSS Merging, do you get an error in your error log?
I guess the problem is the css file cannot generate because of timeout error, or other.
When you enable the CSS Merging, do you get an error in your error log?