found error in filenames.

One array was too short. This had nothing to do with long filenames, other than if they were 12 characters exactly, which could only happen if the extension and the text before were filled completely

Marlin/Configuration_adv.h

@@ -162,6 +162,9 @@ const int dropsegments=5; //everything with less than this number of steps will
 // be commented out otherwise
 #define SDCARDDETECTINVERTED 
 
+#ifdef ULTIPANEL
+ #undef SDCARDDETECTINVERTED
+#endif
 //===========================================================================
 //=============================Buffers           ============================
 //===========================================================================

Marlin/cardreader.cpp

@@ -53,7 +53,7 @@ void  CardReader::lsDive(const char *prepend,SdFile parent)
  
   while (parent.readDir(p) > 0)
   {
-    if( DIR_IS_SUBDIR(&p) && lsAction!=LS_Count && lsAction!=LS_GetFilename)
+    if( DIR_IS_SUBDIR(&p) && lsAction!=LS_Count && lsAction!=LS_GetFilename) // hence LS_SerialPrint
     {
 
       char path[13*2];

Marlin/cardreader.h

@@ -45,7 +45,7 @@ public:
   bool saving;
   bool sdprinting ;  
   bool cardOK ;
-  char filename[11];
+  char filename[12];
   bool filenameIsDir;
   int lastnr; //last number of the autostart;
 private: