This may help someone with this allocation error issue. I kept getting the same error the OP got and couldn’t figure out why. Everything has been plotting ok, then this fatal error began occurring at random times, but regularly.
The fix for me was to change the C-Drive swap file from ‘system managed’ to min 10-max 30GB. No more problems.
One last thing. Memory used for plotting does not seem the issue. For example, I use 9216MB/plot & 64 buckets and all is good.