2 files changed, 4 insertions, 4 deletions
diff --git a/src/main/java/org/traccar/web/OverrideFilter.java b/src/main/java/org/traccar/web/OverrideFilter.java
index 708632bc1..e6e02514c 100644
--- a/src/main/java/org/traccar/web/OverrideFilter.java
+++ b/src/main/java/org/traccar/web/OverrideFilter.java
@@ -45,12 +45,12 @@ public class OverrideFilter implements Filter {
     public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
             throws IOException, ServletException {
 
-        CharResponseWrapper wrappedResponse = new CharResponseWrapper((HttpServletResponse) response);
+        ResponseWrapper wrappedResponse = new ResponseWrapper((HttpServletResponse) response);
 
         chain.doFilter(request, wrappedResponse);
 
         byte[] bytes = wrappedResponse.getCapture();
-        if (wrappedResponse.getContentType().contains("text/html")
+        if (wrappedResponse.getContentType() != null && wrappedResponse.getContentType().contains("text/html")
                 || ((HttpServletRequest) request).getPathInfo().endsWith("manifest.json")) {
 
             Server server;
diff --git a/src/main/java/org/traccar/web/CharResponseWrapper.java b/src/main/java/org/traccar/web/ResponseWrapper.java
index 477fe7928..7c06b67b8 100644
--- a/src/main/java/org/traccar/web/CharResponseWrapper.java
+++ b/src/main/java/org/traccar/web/ResponseWrapper.java
@@ -22,12 +22,12 @@ import javax.servlet.http.HttpServletResponseWrapper;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 
-public class CharResponseWrapper extends HttpServletResponseWrapper {
+public class ResponseWrapper extends HttpServletResponseWrapper {
 
     private final ByteArrayOutputStream capture;
     private ServletOutputStream output;
 
-    public CharResponseWrapper(HttpServletResponse response) {
+    public ResponseWrapper(HttpServletResponse response) {
         super(response);
         capture = new ByteArrayOutputStream(response.getBufferSize());
     }