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....that is not one of: d , g , i , m , s , u , v , or y . It may also...(allowed) flags are d , g , i , m , s , u , v , and y . They are...