Index: class.c
==================================================================
--- class.c
+++ class.c
@@ -2076,21 +2076,21 @@
   unsigned char*p;
   if(!data) return;
   for(i=0;i<size-3;) {
     n=data[i]|(data[i+1]<<8);
     if(!n) break;
-    if(n>=0x4000) fatal("Malformed CLASS.DEF lump\n");
+    if(n>=0x4000) fatal("Malformed CLASS.DEF lump (invalid class number %d)\n",n);
     i+=2;
     p=data+i;
     while(i<size && data[i++]);
     if(i==size && data[i-1]) fatal("Malformed CLASS.DEF lump\n");
     initialize_class(n,CF_NOCLASS2,p);
   }
   i+=2;
   for(;i<size-3;) {
     n=data[i]|(data[i+1]<<8);
-    if(n<256 || n>=0x4100) fatal("Malformed CLASS.DEF lump\n");
+    if(n<256 || n>=0x4100) fatal("Malformed CLASS.DEF lump (invalid message number %d)\n",n);
     n-=256;
     i+=2;
     p=data+i;
     while(i<size && data[i++]);
     if(i==size && data[i-1]) fatal("Malformed CLASS.DEF lump\n");

Index: edit.c
==================================================================
--- edit.c
+++ edit.c
@@ -77,11 +77,11 @@
     sqlite3_str_appendchar(s,1,0);
   }
   sqlite3_str_appendchar(s,2,0);
   for(i=0;i<0x4000;i++) if(mu[i/8]&(1<<(i&7))) {
     sqlite3_str_appendchar(s,1,i&255);
-    sqlite3_str_appendchar(s,1,i>>8);
+    sqlite3_str_appendchar(s,1,(i+256)>>8);
     sqlite3_str_appendall(s,messages[i]);
     sqlite3_str_appendchar(s,1,0);
   }
   // End of data
   size=sqlite3_str_length(s);