I am running 10.11.5 on a CMP 5,1 and my usb mouse cursor keeps freezing. If I disconnect the mouse from USB port and reconnect, the cursor is unfrozen. Everything else works normally, including Apple trackpad. What appears to be happening is that the Mac somehow loses track of the USB mouse. The same thing happens with both of two old, generic usb mice which I have tried. Neither mouse was failing, AFAIK. This also happens whether or not the mouse is connected to any of the native usb 2...
USB mouse cursor keeps freezing
USB mouse cursor keeps freezing