diff --git a/wled00/fcn_declare.h b/wled00/fcn_declare.h
index ff44bbd9..38a18b09 100644
--- a/wled00/fcn_declare.h
+++ b/wled00/fcn_declare.h
@@ -93,6 +93,7 @@ bool readObjectFromFileUsingId(const char* file, uint16_t id, JsonDocument* dest
 bool readObjectFromFile(const char* file, const char* key, JsonDocument* dest);
 void updateFSInfo();
 void closeFile();
+void invalidateFileNameCache();   // WLEDMM call when new files were uploaded
 
 //hue.cpp
 void handleHue();
diff --git a/wled00/file.cpp b/wled00/file.cpp
index 9d6e6a1e..84f99c09 100644
--- a/wled00/file.cpp
+++ b/wled00/file.cpp
@@ -407,10 +407,33 @@ static String getContentType(AsyncWebServerRequest* request, String filename){
   return "text/plain";
 }
 
+// WLEDMM
+static bool haveLedmapFile = true;
+static bool haveIndexFile = true;
+static bool haveSkinFile = true;
+static bool haveICOFile = true;
+static bool haveCpalFile = true;
+void invalidateFileNameCache() { // reset "file not found" cache
+  haveLedmapFile = true;
+  haveIndexFile = true;
+  haveSkinFile = true;
+  haveICOFile = true;
+  haveCpalFile = true;
+}
+
 bool handleFileRead(AsyncWebServerRequest* request, String path){
   DEBUG_PRINTLN("WS FileRead: " + path);
   if(path.endsWith("/")) path += "index.htm";
   if(path.indexOf("sec") > -1) return false;
+
+  // WLEDMM shortcuts
+  if ((haveLedmapFile == false) && path.equals("/ledmap.json")) return false;
+  if ((haveIndexFile == false)  && path.equals("/index.htm")) return false;
+  if ((haveSkinFile == false)   && path.equals("/skin.css")) return false;
+  if ((haveICOFile == false)    && path.equals("/favicon.ico")) return false;
+  if ((haveCpalFile == false)   && path.equals("/cpal.htm")) return false;
+  // WLEDMM toDO: add file caching (PSRAM) for /presets.json an /cfg.json
+
   String contentType = getContentType(request, path);
   /*String pathWithGz = path + ".gz";
   if(WLED_FS.exists(pathWithGz)){
@@ -421,5 +444,13 @@ bool handleFileRead(AsyncWebServerRequest* request, String path){
     request->send(WLED_FS, path, contentType);
     return true;
   }
+  //USER_PRINTLN("WS FileRead failed: "  + path + " (" + contentType + ")");
+
+  // WLEDMM cache "file not found" results (reduces LED flickering during UI activities)
+  if (path.equals("/ledmap.json")) haveLedmapFile = false;
+  if (path.equals("/index.htm"))   haveIndexFile = false;
+  if (path.equals("/skin.css"))    haveSkinFile = false;
+  if (path.equals("/favicon.ico")) haveICOFile = false;
+  if (path.equals("/cpal.htm"))    haveCpalFile = false;
   return false;
 }
diff --git a/wled00/wled.h b/wled00/wled.h
index dc3ee12b..36170286 100644
--- a/wled00/wled.h
+++ b/wled00/wled.h
@@ -8,7 +8,7 @@
  */
 
 // version code in format yymmddb (b = daily build)
-#define VERSION 2404260
+#define VERSION 2404280
 
 // WLEDMM  - you can check for this define in usermods, to only enabled WLEDMM specific code in the "right" fork. Its not defined in AC WLED.
 #define _MoonModules_WLED_
diff --git a/wled00/wled_server.cpp b/wled00/wled_server.cpp
index a08e9ea6..f3fe1c08 100644
--- a/wled00/wled_server.cpp
+++ b/wled00/wled_server.cpp
@@ -58,6 +58,7 @@ void handleUpload(AsyncWebServerRequest *request, const String& filename, size_t
     request->_tempFile.close();
     USER_PRINT(F("File uploaded: "));  // WLEDMM
     USER_PRINTLN(filename);            // WLEDMM
+    invalidateFileNameCache();         // WLEDMM
     if (filename.equalsIgnoreCase("/cfg.json") || filename.equalsIgnoreCase("cfg.json")) { // WLEDMM
       request->send(200, "text/plain", F("Configuration restore successful.\nRebooting..."));
       doReboot = true;