Update runtime files
diff --git a/runtime/doc/message.txt b/runtime/doc/message.txt
index fbf4ce2..2dc7535 100644
--- a/runtime/doc/message.txt
+++ b/runtime/doc/message.txt
@@ -1,4 +1,4 @@
-*message.txt* For Vim version 8.2. Last change: 2020 Dec 29
+*message.txt* For Vim version 8.2. Last change: 2021 Jul 31
VIM REFERENCE MANUAL by Bram Moolenaar
@@ -774,6 +774,14 @@
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
+<
+ *E928* *E889* *E839* >
+ E928: String required
+ E889: Number required
+ E839: Bool required
+
+These happen when a value or expression is used that does not have the
+expected type.
==============================================================================
3. Messages *messages*