I just updated an attachment on a proposed project that will make it much clearer. As there are 25 proposals on it, is there a way to make sure everybody sees it.
Once we leave a bid, that's it. There is no way to know if an RFP has been revised. You would have to respond to freelancers and send the revised attachment via the message room.
A mod may come along to correct me on this, but unless I go and look at my proposals, I would have no way of knowing changes were made, and even then I think it would just take me back to the original proposal..
re: "As there are 25 proposals on it, is there a way to make sure everybody sees it."
Sorry, no, there's no way to easily do that.
You would have to contact each candidate individually.
If I were you, I would not worry so much about making sure that all the candidates can see the changed attachment. As long as it doesn't completely change the nature of the job, they don't actually care.
Focus on identifying the 6 best candidates you think best fit your project's needs. Then invite them to interview, but in your message to them, send them the revised attachment. After talking to these 6, hire the 3 best candidates to do the first phase of the project. From those 3, choose the best and work with that individual to complete the project.