Symetrik Domino Consulting

Have you ever seen this message when opening a mail database? From time to time we see this after an upgrade. Normal Fixup, Compact, Updall, and even template replace will not fix the issue.

However, Compact -D will do the trick.
The -D switch discards any built view indexes

You can try this for B-tree structure is invalid! errors as well.

For good measure you can run Updall -R afterwards to rebuild all the view indexes.