wro4j-core/src/main/java/ro/isdc/wro/http/support/RedirectedStreamServletResponseWrapper.java
private void onError(final int sc, final String msg) {
    LOG.debug("Error detected with code: {} and message: {}", sc, msg);
    final OutputStream emptyStream = new ByteArrayOutputStream();
    printWriter = new PrintWriter(emptyStream);
    servletOutputStream = new DelegatingServletOutputStream(emptyStream);
  }
private void onError(final int sc, final String msg) {
    LOG.debug("Error detected with code: {} and message: {}", sc, msg);
    final OutputStream emptyStream = new ByteArrayOutputStream();
    printWriter = new PrintWriter(emptyStream);
    servletOutputStream = new DelegatingServletOutputStream(emptyStream);
  }
Use an empty stream to avoid container writing unwanted message when a resource is missing.

@param sc
status code.
@param msg