[Branched from: Dreamweaver Erased my files]

The thread you resurrected from 2012 is unrelated to your question so I moved and branched this question to a new topic for you.

Please read about using Less/Sass (aka CSS preprocessors) in Dreamweaver.   .scss and .css are two sides of the same coin.

https://helpx.adobe.com/dreamweaver/using/css-preprocessors.html

Still think this is a dreamweaver issue.  I am working currently and the power has not gone out. I added a file styles.scss to my directory along side of my styles.css file . The delete it. Now I notice my stylesheet is not loading. Not loading because it is now blank. No problem - I must have deleted it accidentally. Nope  - undo doesn't seems to do anything but undo all the html changes I have done. It is gone!!! i will be able to get a version from Dropbox but this is a bug. I have had dreamweaver go into what I call psychomode where it deletes chunks of html and undos start throwing code all over the place. If you don't quit immediately you will save bad code.