Update runtime files.
diff --git a/runtime/doc/message.txt b/runtime/doc/message.txt
index b2d0578..5eeba0c 100644
--- a/runtime/doc/message.txt
+++ b/runtime/doc/message.txt
@@ -1,4 +1,4 @@
-*message.txt* For Vim version 8.0. Last change: 2017 Jan 02
+*message.txt* For Vim version 8.0. Last change: 2017 Mar 25
VIM REFERENCE MANUAL by Bram Moolenaar
@@ -768,6 +768,13 @@
You tried to execute a command that is neither an Ex command nor
a user-defined command.
+ *E943* >
+ Command table needs to be updated, run 'make cmdidxs'
+
+This can only happen when changing the source code, when adding a command in
+src/ex_cmds.h. The lookup table then needs to be updated, by running: >
+ make cmdidxs
+
==============================================================================
3. Messages *messages*