When your web site is using internet site documents for configuration, then any urls with !open (eg !OpenForm, !OpenDocument) no longer work. You can confirm by changing the url of pages in LDD to !OpenDocument.
Any thoughts on workarounds?
Subject: using !Open versus ?Open with Internet Site documents…
On the server document, in the ‘Internet Protocols’ tab, in the ‘Domino Web Engine’ sub-tab, in the ‘Conversion/Display’ section (phew!) there is a field ‘Make this site accessible to web search site crawlers’.
Enable this field and all should be well.
HTH
TomK