Missing proxy appears

One of these has to be clicked on to activate the process. I am "experimenting with a shorter clip now and I see it is taking a long time. I presume it also adds to higher data. Since I have "finished" productions saved on external drive, i will be running out of space pretty soon. Is that corrects?

Thanks Tom. It was successful.

My question is connected to "surprise" to see these proxy icons - haven't open FCP for a while. You explained well what to do about it. It is true that I might not need to transcode.

However I have some longer footage uploaded into FCP from which I take only shorter clips out and produce as separate pieces for YouTube or Vimeo. All of those partially used longer footage has now this proxy icon.

Thanks

two icons to be clicked

create optimized media

or

create proxy media

or both? Don't know the difference

Thank you THANK YOU Phew!