diff --git a/lib/obp60task/ImageDecoder.cpp b/lib/obp60task/ImageDecoder.cpp
index 545ace6..25783d2 100644
--- a/lib/obp60task/ImageDecoder.cpp
+++ b/lib/obp60task/ImageDecoder.cpp
@@ -2,13 +2,22 @@
 #include <mbedtls/base64.h>
 
 // Decoder for Base64 content
-bool ImageDecoder::decodeBase64(const String& base64, uint8_t* outBuffer, size_t outSize, size_t& decodedSize) {
+bool ImageDecoder::decodeBase64(const char* base64, size_t base64Len, uint8_t* outBuffer, size_t outSize, size_t& decodedSize) {
+    if (base64 == nullptr) {
+        decodedSize = 0;
+        return false;
+    }
     int ret = mbedtls_base64_decode(
         outBuffer,
         outSize,
         &decodedSize,
-        (const unsigned char*)base64.c_str(),
-        base64.length()
+        (const unsigned char*)base64,
+        base64Len
     );
     return (ret == 0);
 }
+
+// Decoder for Base64 content
+bool ImageDecoder::decodeBase64(const String& base64, uint8_t* outBuffer, size_t outSize, size_t& decodedSize) {
+    return decodeBase64(base64.c_str(), base64.length(), outBuffer, outSize, decodedSize);
+}
diff --git a/lib/obp60task/ImageDecoder.h b/lib/obp60task/ImageDecoder.h
index 473b168..5bae456 100644
--- a/lib/obp60task/ImageDecoder.h
+++ b/lib/obp60task/ImageDecoder.h
@@ -5,5 +5,6 @@
 
 class ImageDecoder {
 public:
+    bool decodeBase64(const char* base64, size_t base64Len, uint8_t* outBuffer, size_t outSize, size_t& decodedSize);
     bool decodeBase64(const String& base64, uint8_t* outBuffer, size_t outSize, size_t& decodedSize);
 };
diff --git a/lib/obp60task/PageNavigation.cpp b/lib/obp60task/PageNavigation.cpp
index 262bce1..9924f84 100644
--- a/lib/obp60task/PageNavigation.cpp
+++ b/lib/obp60task/PageNavigation.cpp
@@ -4,6 +4,7 @@
 #include "OBP60Extensions.h"
 #include "NetworkClient.h"      // Network connection
 #include "ImageDecoder.h"       // Image decoder for navigation map
+#include <mbedtls/base64.h>
 
 #include "Logo_OBP_400x300_sw.h"
 
@@ -432,13 +433,21 @@ bool showValues = false; // Show values HDT, SOG, DBT in navigation map
 
             // Decode Base64 content to image
             size_t decodedSize = 0;
-            bool decodeOk = decoder.decodeBase64(b64, imageData, imgSize, decodedSize);
+            bool decodeOk = decoder.decodeBase64(b64, b64len, imageData, imgSize, decodedSize);
             if (!decodeOk || decodedSize < requiredBytes){
+                int base64Ret = mbedtls_base64_decode(
+                    nullptr,
+                    0,
+                    &decodedSize,
+                    (const unsigned char*)b64,
+                    b64len
+                );
                 LOG_DEBUG(GwLog::ERROR,
-                    "Error PageNavigation: decode failed (ok=%d, decoded=%u, required=%u)",
+                    "Error PageNavigation: decode failed (ok=%d, decoded=%u, required=%u, b64ret=%d)",
                     decodeOk ? 1 : 0,
                     (unsigned int)decodedSize,
-                    (unsigned int)requiredBytes
+                    (unsigned int)requiredBytes,
+                    base64Ret
                 );
                 free(b64);
                 free(imageData);