The JavaScript exception "invalid regular expression flag" occurs when the flags in a regular expression contain any flag that is not one of: d, g, i, m, s, u, v, or y. It may also be raised if the expression contains more than one instance of a valid flag, or when the u and v flags are used together....Skip to search Skip to select language Article Actions English (US)...(US) Remember language Deutsch Español Français 日本語 한국어 Português...