Everyone got a full skill reset with version 172.0. This will happen again with 172.x (bug fixes) and most likely again with 173 (continued skill balance). In the case of, 172.x: Due to several issues having been discovered but having to keep schedule are going to be patched in for a few days while a quick fix patch is compiled.
Most notably, I must beg forgiveness of every Assassin and Shadow Runner. There are a few other issues, less drastic but nevertheless to be fixed ASAP. There will be an extra maintenance as soon as the fixes are ready.