avatar is a white particle cloud

you're going to see white particle clouds often in Second Life.  it might be someone else, or it might be you.
sometimes the cloud seems to hang around for quite a while.  don't worry, your avatar isn't broken :)
this is a function of the Rendering Engine of Second Life, and there is a simple fix.
you need to access Advanced on the top menu. if you don't see Advanced, you can activate it by pressing: CTRL + ALT + D
click on Advanced, scroll down the list and click on Debug Settings
a Dialog Window will open at the bottom left of the screen.
enter: renderUnloadedAvatar (all one word, no spaces)
when that shows, change the default setting to True, and close the Dialog Window.
exit out of the Second Life client, and restart it.
you should see a noticeable difference in the rendering of avatars, and you should never see white particle clouds again :)
rendering is also affected by Avatar Rendering Cost.  I'll cover ARC in another post.