I have several search scopes set up in Search Administration, one of which is the default All Content scope which includes everything but items with a contentclass of SPSPeople. On my advanced search page in the Search Center, all of these scopes are available for searching, and All Content is selected as the default scope. If a user selects another scope in addition to the All Content scope (which is admittedly redundant), the following appears in the results view:
Your search cannot be completed because of a service error. Try your search again or contact your administrator for more information.
This only happens with the All Content scope. There are other scopes which are also supersets of smaller scopes, and these can be selected together with their sub-scopes without problems. Also, the All Content scope works fine when used by itself. There are no relevant messages I can find in the ULS logs.
I know that this is a silly search to do and don't expect it to be done intentionally. The problem comes when a user forgets to uncheck "All content" when checking another scope -- I'd rather they still get results (maybe it will even be apparent that they selected their scope improperly), than get this error message.
One workaround would be to remove the All Content scope from the Advanced Search display group in the site collection settings. But that requires me to select a different (narrower) default scope, and I need the Advanced Search page to default to searching all content.
Can anyone help me out? Thanks!