Hello, I'm still starting out with maya, and I seem to be stuck. (I've checked many forums but haven't found this problem yet online) My soft selection was working fine previously, but now everytime i hit "b", nothing happens, and if I hold down LMB and drag, I just see a blue circle, but it doesn't expand my selection or do anything at all. Hope someone can help, thanks!
Can't really tell what the problem is but there are two things you could try that i can think of on the spot.
Easiest, double click your tool in the toolbar and hit reset. If your lucky it will then reset your soft selection settings to default settings.
If that doesn't work there is alway the universal problem solver for many unknown problems in maya. Whenever maya starts to get weird you can always try to delete/rename the preference folder in "documents/maya/2015-x64/pref" and restart maya. Maya will then recreate this folder when it starts up again but do note this will reset all settings you've made inside maya, included shelfs etc.