Been discussing this problem on a different thread… just in case someone is reading and uses FileZilla – the problem is with the upload (weird I know)… something about file/tree structures… Anyway, if you download the 3.6.1 RC1 version from here: https://filezilla-project.org/download.php?type=client&beta=1
…and rewrite over your old install…things should be back to normal (I had to reselect “use visual editor” out of my user account and refresh a couple of times by the way)
Just in case…
Bob