Open "command or conda prompt" and run:
conda update conda
conda update anaconda
It's a good idea to run both command twice (one after the other) to be sure that all the basic files are updated.
This should put you back on the latest 'releases', which contains packages that are selected by the people at Continuum to work well together.
If you want the last version of each package run (this can lead to an unstable environment):
conda update --all
Hope this helps.
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