When I schedule report, it allows HTML options, but when receiving the email notification after report has been successfully archived. It compliants about the "in format "html" cannot be sent as attachment, as html is currently not supported. Please update the parameters in the schedule. Falling back to sending the URL.
Version 4.5 SP1.
Report Configuration Changes by User_09-05-2011-10:00:00.html has been successfully archived.
Report 'Configuration Changes by User_09-05-2011-10:00:00.html' in format 'html' cannot be sent as attachment, as html is currently not supported. Please update the parameters in the schedule. Falling back to sending the URL.
Please visit https://esm:9443/arcsight/app?service=external/ReportResultsTop&sp=S%3A53VQNzIBABDV6ds3pck6RA%3D%3D
attaching html is not supported, I get the same error on my system (same ESM version) but you can find the report under Reports --> Archives in your personel folder and if you have configured to open html in an external browser you will see it there.