After upgrading to DW 9.7.3
This only happens when some specific search params are used like 'maintenance' or 'core' also first letter capital seems to trigger the same error:
An error occurred while attaching module (Dynamicweb.Frontend.Content)
System.ArgumentOutOfRangeException: Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: startIndex at System.String.IndexOf(String value, Int32 startIndex, Int32 count, StringComparison comparisonType) at Dynamicweb.WeightedSearch.Frontend.GetSummary(String text, String word) at Dynamicweb.WeightedSearch.Frontend.RenderSearchResults(String q, ResultItemCollection searchResults) at Dynamicweb.WeightedSearch.Frontend.GetContent() at Dynamicweb.Frontend.Content.GetModuleOutput(Paragraph paragraph, PageView pageview)
This is a standard searchv1 with the standard .html templates
Rgds