If an attachment happens to have a duplicate name or file extension wrong format, I get a message telling me so and everything typed beforehand is lost, preview for some reason does not work. Type in post add a few pictures and hey presto duplicate name iges instead of igs file extension for exampler and everything disappears, time to start post from scratch. (OS win 8.1, Browser Firefox)
Today I went to post and again forgot to back up text or type in notepad, lost everything and no time to redo so could not post an update due to lack of time. The problem was with file type today as I added an igs file with iges extension, result lost effort and no post until I have time to redo.
Error trapping needs to be done earlier or input saved and user returned to it to allow corrections, just annoying and this is only forum that does this to me.