If this is a 450, it is not an SQL security error. I went through this with a customer just a couple of months ago. It required a patch to resolve and is now a known problem with Avaya. I don't think the patch has been released yet but it did resolve the issue.
The problem only occurs when you are trying to generate reports that contain a large amount of data, like the Agent Activity Report, for more than a couple of days. If you run those same reports for just a 24 hour period, they will likely print ok but anything beyond that, you get exactly what you are describing.
So, to resolve it, you will have to open a case with Avaya and they will have to patch your RCC server. It's not an issue within the BCM itself. The patch I referenced earlier was for a slightly different issue but if you do load it, remove the existing RCC client from your server and install the new one. It might fix it.