patch 7.4.2250
Problem:    Some error message cannot be translated.
Solution:   Enclose them in _() and N_(). (Dominique Pelle)
diff --git a/src/spell.c b/src/spell.c
index 8d8689b..5fd38b3 100644
--- a/src/spell.c
+++ b/src/spell.c
@@ -2470,7 +2470,7 @@
 		 * destroying the buffer we are using... */
 		if (!bufref_valid(&bufref))
 		{
-		    ret_msg = (char_u *)"E797: SpellFileMissing autocommand deleted buffer";
+		    ret_msg = (char_u *)N_("E797: SpellFileMissing autocommand deleted buffer");
 		    goto theend;
 		}
 #endif