A year or two ago I setup a number of Nessus servers monitoring a few /16 network blocks.
Now I find that generating reports doesn't work, it seems to be getting out-of-memory errors while attempting to perform XSL translations on the reports.
A while back I wrote a script that aggregates reports together from various Nessus servers and creates a single report. This is useful because you can have some sections of your 'production' network scanned with one profile and others with a second profile - the script can put it all together as a single report for the 'Production' network - mail stakeholders with summary information etc.
So luckily I can get around the OOM errors by slicing up my networks into smaller chunks and scanning separately and gluing back together afterwards automagically!
I suspect others are in a far crappier situation. I can't share the script here but will help people out who are trying to do the same thing, lots of people appear to be struggling with this:
Wouldn't it be nice if Tenable fix this before we all find better alternatives?