nearly everything in my inventory was taken yesterday

[BrianDavidson]

yesterday my inventory was empt. All of the folders are there but there sint anything in them

[Rolig Loon]

It's not time to panic yet.  All that's happened, probably, is that your local inventory cache has been corrupted.  Your viewer never touches your real inventory, which is safe on Linden Lab servers.  The cache on your own machine is a copy that is renewed each time you log in and is updated as you add or remove things.  If you had a flaky Internet connection during login, the cache may have been damaged. That's especially likely if your inventory is large or has folders with a lot of things in them. So, force your viewer to get a new copy.

Here's how >>> http://wiki.phoenixviewer.com/fs_cache_clear .  Those instructions were written by the Firestorm staff, but they work for any viewer.  IMO, the most important line in them is the one that says, "While inventory repopulates, do not teleport anywhere, and do not attempt to access anything in your inventory."  Just be patient.

That should fix the problem.  If it doesn't, you may need to tend to the quality of your Internet connection.  Avoid using wifi, for example.  Use a direct cable or DSL connection instead.  Reboot both your router and your modem and restart your computer.