invalid escape sequence

[K Fred]

Hi all，

   There are an error in my regex expression, exception below:

Exception in thread "main" com.google.re2j.PatternSyntaxException: error parsing regexp: invalid escape sequence: `\u`

at com.google.re2j.Parser.parseEscape(Parser.java:1445)

at com.google.re2j.Parser.parseClassChar(Parser.java:1460)

at com.google.re2j.Parser.parseClass(Parser.java:1665)

at com.google.re2j.Parser.parseInternal(Parser.java:856)

at com.google.re2j.Parser.parse(Parser.java:788)

at com.google.re2j.RE2.compileImpl(RE2.java:186)

at com.google.re2j.Pattern.compile(Pattern.java:147)

at com.google.re2j.Pattern.compile(Pattern.java:105)

The origin expression is: 

      [?&](mv=)(?P<mv>[0-9]{5,10})[&/\?\u0000]