Exception in RegExp compiling in Restlets

at java.util.regex.Pattern.error(Pattern.java:1650)
at java.util.regex.Pattern.escape(Pattern.java:1977)
at java.util.regex.Pattern.atom(Pattern.java:1863)
at java.util.regex.Pattern.sequence(Pattern.java:1794)
at java.util.regex.Pattern.expr(Pattern.java:1687)
at java.util.regex.Pattern.compile(Pattern.java:1397)
at java.util.regex.Pattern.<init>(Pattern.java:1124)
at java.util.regex.Pattern.compile(Pattern.java:817)
at org.restlet.util.Template.getRegexPattern(Template.java:598)
at org.restlet.util.Template.match(Template.java:858)
at org.restlet.Route.score(Route.java:422)
at org.restlet.util.RouteList.getBest(RouteList.java:82)
at org.restlet.Router.getNext(Router.java:346)
at org.restlet.Router.handle(Router.java:442)
at com.noelios.restlet.ext.servlet.ServletConverter.service(ServletConverter.java:129)
at org.nuxeo.ecm.platform.ui.web.restAPI.RestletServlet.service(RestletServlet.java:131)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.nuxeo.wss.servlet.WSSFilter.doFilter(WSSFilter.java:115)