When I am trying to install Sequoyah in Eclipse from Help -> Install New Software , either through online installation or using downloaded local site archive it gives error Duplicate Location.
Or even first time when I select the downloaded archived file it does not show the files rather check box with There are no categorized items
please help. I even tried to delete Eclipse and unpack and did all this again but same problem.

this error means that the location you are trying to add exists already. Try to search sequoyah in the “type filter text” box, and uncheck the “Group items by category” checkbox