The line numbers and column numbers are meaningless in the Exception. This is quite annoying because for now this is the only information we got.
For some rubish in an inline styling: WARNING: com.sun.javafx.css.parser.CSSParser declaration Expected COLON at ?[-1,-1]
For some rubish in the first line of a CSS file: WARNING: com.sun.javafx.css.parser.CSSParser parse Expected LBRACE at file:/Users/jfdenise/assets/mycss1.css[8631,3]