Unstable file

[Mike MSC]

I get this message every so often when the site I'm working on has a failure of some sort and closes down. When I re-open it, there is a box saying that an unstable file has been detected and I might have to re-do any recent changes. When the site does open again I do indeed have to make the changes again.

My question is - what makes the site "unstable"?

[antonsvideo]

often pasting text from an Office document will cause an unstable site because the paste operation brings along tons of Office formatting code

to paste correctly, set the paste default to unformatted text, this will strip the formatting
https://www.videoproductions.com.au/...te-default.png