I am trying to export a multitrack mixdown that is almost an hour long. It's big, I get it, but I cannot for the life of me get past the bad allocation error. I've tried exporting it in bits, I've changed the available RAM for Audition, and I've tried restarting, etc. I don't know what to do, please help me.
Since you haven't even told us whether this is a Mac or a PC we couldn't even begin to make any suggestions about what might be causing it. And we'd need to know a lot more about the conditions that have caused this, and exactly what the error message says (including whether it was Audition or the operating system that produced it), etc.
For a start though, have you tried just mixing it down to a file, rather than exporting it?