Have VMware? Update your Fedora?
Turns out that 2.6.40 breaks VMWare pretty badly. This is VMWare’s fault because they’re using the old locking in the kernel. They’re normally pretty quick about this stuff but I was unable to find an “official” fix. We’ll wait and see.
In the mean time, this patch will get you working.
To use it, you need to download VM Player or Workstation, you need to fail the install once, then apply the patch. Then try starting VMWare player/workstation again. It’s not the most elegant thing, but it works. Also even though the patch is for 2.6.39, it will work on 2.6.40.