Accidentally flagged a post, how to undo
I was going to click the title and accidentally clicked flag and now don't know how to get back to it to un flag?
was on mobile
It's possible it's now marked '[flagged][dead]' and unless you have enabled 'showdead=yes' in your profile you won't see [dead] links.
Normally, the "flag" text changes to "unflag". If you click that, it undoes the flagging. This does require that you be able to find the post that you flagged. Are you saying that it disappeared when you flagged it?