Most likely it is caused because the HDDs are not configured in RAID.
First make sure that you have a RAID matrix (after POST, if you get a message stating that Intel ESRT2 is starting up).
Without any RAID matrix configured, Raid Web Console will not start, as it is not necessary when using HDDs in non-RAID configurations.
There was a configured raid, but Bios setup was configured as 'Intel Matrix' instead of ESR2. I'm now reinstalling system with an ESR2 Raid volume.