QGIS 2.8.2 on windows 8.1 produces the below error every time it is closed.
in the past when I disabled my plugins, the minidump error message didn't go away
But when I just moved (or cleared) the contents of the plugin folder, that is C:\Users\Rob.qgis2\python\plugins, the minidump error stopped
then I just re-installed my plugins one by one. I have also done this to improve QGIS loading speed. Eventually too many or a particular plugin that I haven't isolated bogs my QGIS system down.