>I have a parameterized view which I then index on:
>
>INDEX ON v_ViewName.cFieldName TAG cFieldName [Character field]
>and
>INDEX ON v_ViewName.dFieldName TAG dFieldName [DateTime field].
>
>I get the subject error message 'INDEX does not accept NULL'. I find no reference in the documentation, Hacker's Guide, or FoxWiki.
>
>How could I resolve this isssue other than changing the view to substitute blanks / empty DateTime?

From VFP 7 help: "Index does not accept NULL (Error 1886)
Your primary or candidate key index expression evaluated to NULL, which is an invalid value for these types of indexes.
Change record values so the expression does not evaluate to NULL".

You can use NVL() function to convrt Null to some other value in the view or in the index expression.