trouble posting .blend file

Blend file not uploading. What format does the blend file have to be to upload it to the forum? Or how do I do it? Ive done it many times before, but am in a brain freeze again. Does it have to be a zip file? Whats the simplest way to do it?

Sorry bout the one millionth repeat question…

How large is the .blend file? Are you getting any error message?