If you're in the Windows Insider program and running preview builds, your PC should have upgraded overnight to build 10586.3. The bump comes from installing KB 3105211 on Windows 10 beta build 10586.
Microsoft isn't saying anything, of course, but it seems like a good idea to make sure your Insider beta PC is on the latest build -- 10586.3 -- before Windows 10 version 1511 (also known as Fall Update and/or TH2) arrives. I've seen sporadic reports of problems installing the KB 3105211 patch -- the OS Build number is 10586.0 -- although the problems sometimes disappear if you give Windows a long time to install it.
Here's how to check your version number:
In the Cortana search box, type
run and hit Enter. Then type
winver and hit Enter again. You should see a version box like that in the figure.
(If you're running plain old Windows 10 RTM, you'll see version 10240, whether the analogous KB 3105213 patch was installed or not.)
With Win10 version 1511 coming up soon (rumor still says Microsoft is aiming for Thursday), it would be a good idea to make sure you're all caught up. If you still see OS build 10586.0, try re-installing last night's patches. If that doesn't work, get over to the Microsoft Answers forum and give a shout.