Can i convert an SESX file outside of Audition

My question is: can you convert an sexs file to work in another daw program??  Am I trapped in using Audition?

In this day and age of cheap storage there really shouldn't be an excuse for running out of space.

"Frustrated I clicked Save As , and saving an SESX file"

I don't understand what you are saying here?

You clicked save as and saved it elsewhere - and that is a problem how?

"Is there any way outside Audition that this can be converted to a WAV our mp3"

When you say "this" do you mean convert an sesx to wav or mp3?

If that is what you mean the answer is no.  The sesx is a project session file containing references (among other things) to your audio.

You audio should have been saved (as wav probably) already during the save as

"Also any advice on how to stop that awful error message from appearing again"

You already know the answer to that - have plenty of free space available before your next session