I read the guide here: http://ladderslasher.d2jsp.org/index.php?g=7 for transmuting.

Basically, when I put a magical item inside 1 of the boxes and click transmute, I'm supposed to get an essence back right? Well, it never worked for me. I tried everything, like putting 2 items of magical property inside, but nothing worked. How do you even transmute?

Put one in, and then click the correct buttons to pass the mute, and recieve an essence

For some reason, I only see the "Transmute" button, and when I click it, nothing happens

this is quite useful