Getting an error about duplicate sources, how can I get around this?
I went into synaptic ("Ubuntu Software Center") icon.
I went into the Ubuntu top bar indicator (not the winow, the one at the top of your screen) and went into preferences and unchecked the second duplicate (shown here when both were still checked):
Then I was able to
open your terminal and type this
then in that file look for duplicate entries regarding those error lines and remove them .
Note: take a backup with this command before doing above process .