As of today, mouse scrolling no longer works on any guest OS I have installed. All OSs are Ubuntu 64-bit (either 12.04 or 14.04). Installing a fresh guest OS does not solve the problem, nor does reinstalling Workstation.
I have ported a VM over to VirtualBox, and the mouse scroll is working there.
I had added the following to the .vmx file of one guest OS yesterday:
mouse.vusb.enable = "TRUE"
usb.generic.allowHID ="TRUE"
mouse.vusb.useBasicMouse = "FALSE"
However, the mouse was behaving correctly yesterday, and this is just one of several affected OSs.
Host OS: Win 7 Pro 64-bit
Could this have been caused by yesterday's round of Windows updates?