Security slider is broken in second RC for Tor Browser 8 on Windows
In #27401 (moved) we fixed JavaScript being disabled in start-up and (I believe) the security slider not working.
However, testing with the second release candidate for Tor Browser 8 (https://people.torproject.org/~gk/builds/8.0-build4/) shows that this is (still) broken on Windows while at least on Linux it is working. On Windows both 32bit and 64bit bundles disabled JavaScript and the security slider is essentially not working.
To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information