diff --git a/src/hover.cpp b/src/hover.cpp
index 80acb96..04df6f7 100644
--- a/src/hover.cpp
+++ b/src/hover.cpp
@@ -152,7 +152,7 @@ struct Sec_Hover_Fn {
       ended = !display_grouped;
     }
     cur_field_off += field_len;
-    return false;
+    return hovered;
   }
 
   template <typename TStrSize>
@@ -171,14 +171,14 @@ struct Sec_Hover_Fn {
       return;
     }
     u64 field_len = sizeof(TStrSize) + (u64)str_size;
-    hovered = roff < cur_field_off + field_len;
-    if (display_grouped || hovered) {
+    if (display_grouped || roff < cur_field_off + field_len) {
       info.rng = { start + cur_field_off, field_len };
       u8 *buf = arena_push_array_nozero<u8>(arena, str_size + 1);
       memcpy(buf, data + start + cur_field_off + sizeof(TStrSize), str_size);
       buf[str_size] = 0;
       String8 s = { buf, str_size };
       display_val(arena, info.desc, desc_fmt, s);
+      hovered = true;
       ended = !display_grouped;
     }
     cur_field_off += field_len;
@@ -294,6 +294,7 @@ struct Sec_Hover_Fn {
   }
 
   enum Frame_Type {
+    Frame_INVALID,
     Frame_Record,
     Frame_List
   };
@@ -301,10 +302,11 @@ struct Sec_Hover_Fn {
   Frame_Type frame_header(u64 &size, u32 *n_items = nullptr, const char *title = nullptr)
   {
     String8 titlestr = title ? push_str8f(arena, "Frame Header: %s", title) : str8("Frame Header");
-    Frame_Type frame_type = Frame_Record;
-    titled_section(titlestr.c(), [this, &frame_type, &frame_size = size, n_items] {
+    Frame_Type frame_type = Frame_INVALID;
+    titled_section(titlestr.c(), [this, &frame_type, &frame_size = size, n_items, titlestr] {
       i64 size;
       memcpy(&size, data + start + cur_field_off, sizeof(size));
+      printf("frame header %s read size %ld at 0x%lX\n", titlestr.c(), size, start + cur_field_off);
       if (size >= 0) {
         frame_type = Frame_Record;
         field<i64>("Record frame size: %" PRIi64 " B", hover_display_val_le_abs<i64>);
@@ -320,6 +322,7 @@ struct Sec_Hover_Fn {
 
       frame_size = std::abs(size);
     });
+    assert(frame_type == Frame_Record || frame_type == Frame_List);
     return frame_type;
   }
 
@@ -333,7 +336,9 @@ struct Sec_Hover_Fn {
       u64 start_off = cur_field_off;
       u64 size;
       Frame_Type ftype = frame_header(size); 
-      assert(ftype == Frame_Record);
+      if (ftype != Frame_Record)
+        return;
+      
       // DEBUG
       if (size > 100000) {
         printf("read field_frame_size = %lu at offset 0x%lX!\n", size, start + cur_field_off);
@@ -372,17 +377,20 @@ struct Sec_Hover_Fn {
 
   void column_desc(const char *title)
   {
-    titled_section(title, [this] {    
+    titled_section(title, [this, title] {    
       u64 start_off = cur_field_off;
       u64 size;
       Frame_Type ftype = frame_header(size);
-      assert(ftype == Frame_Record);
+      if (ftype != Frame_Record)
+        return;
+
       // DEBUG
       if (size > 100000) {
         printf("read column_desc_size = %lu at offset 0x%lX!\n", size, start + cur_field_off);
         ended = true;
         return;
       }
+
       field_le<i64>("Size: %" PRIi64 " B");
       field<u16>("Column type: %s", [](Arena *arena, String8_Node *prev, const char *fmt, u16 val) {
         const char *readable_col_type = get_column_type_name(val);
@@ -403,21 +411,29 @@ struct Sec_Hover_Fn {
         field_le<double>("Value Min: %f");
         field_le<double>("Value Max: %f");
       }
+
+      assert(cur_field_off >= start_off);
+      if (size < cur_field_off - start_off) {
+        printf("column_desc(%s) should be of size %lu but we allocated %lu bytes for it?\n", title, size, cur_field_off - start_off);
+        return;
+      }
       u64 extra_size = size - (cur_field_off - start_off);
+      printf("extra size: %lu - %lu = %lu\n", size, cur_field_off - start_off, extra_size);
       if (extra_size > 0)
         range("Unknown", extra_size);
     });
   }
 
   template <typename F>
-  void list_frame(const char *title, F &&fn)
+  void list_frame(const char *title, F &&per_elem_fn)
   {
+    if (ended)
+      return;
+
     u64 size;
     u32 n_elems;
     Frame_Type ftype = frame_header(size, &n_elems, title);
-    // assert(ftype == Frame_List);
-
-    if (ended)
+    if (ftype != Frame_List)
       return;
 
     // DEBUG
@@ -427,7 +443,7 @@ struct Sec_Hover_Fn {
       return;
     }
     for (u32 i = 0; i < n_elems; ++i) {
-      fn();
+      per_elem_fn();
       if (ended)
         break;
     }
@@ -437,9 +453,9 @@ struct Sec_Hover_Fn {
   {
     titled_section(title, [this] {
       // TODO: Columns and alias columns are not the same
-      list_frame("Fields", [this] { return field_desc(); });
-      list_frame("Columns", [this] { return column_desc("Column"); });
-      list_frame("Alias Columns", [this] { return column_desc("Alias Column"); });
+      list_frame("Fields", [this] { field_desc(); });
+      list_frame("Columns", [this] { column_desc("Column"); });
+      list_frame("Alias Columns", [this] { column_desc("Alias Column"); });
       list_frame("Extra Type Infos", [this] {
         field_le<u32>("Content identifier: %lu");
         field_le<u32>("Type version from: %lu");
diff --git a/src/root/RMicroFileReader.cxx b/src/root/RMicroFileReader.cxx
index 4ebfc5e..5a4ce7a 100644
--- a/src/root/RMicroFileReader.cxx
+++ b/src/root/RMicroFileReader.cxx
@@ -1224,7 +1224,7 @@ RMicroFileReader::GetNTupleProper(const char *ntupleName)
       RTFString blobName { kBlobClassName };
       RTFKey dummy;
       // FIXME: it seems that sometimes even if IsBigFile() == false we get a big header size!
-      if (fileHeader.IsBigFile())
+      // if (fileHeader.IsBigFile())
          dummy.MakeBigKey();
       fileInfo.rblob_key_header_nbytes = dummy.GetHeaderSize() + blobName.GetSize() + 2 * RTFString{}.GetSize();
       printf("nbytes: %lu\n", fileInfo.rblob_key_header_nbytes);