I tried to add demo content and I too am having issues: (this is just part of the error list)
Import WordPress
Failed to create new user for Charlene Crawford. Their posts will be attributed to the current user.
Failed to import it_exchange_category Electronics
Failed to import it_exchange_tag featured
Failed to import it_exchange_category Memory
Failed to import it_exchange_category Monitor
Failed to import it_exchange_category Motherboard
Failed to import it_exchange_category Processor
Failed to import it_exchange_category Tablet
Failed to import it_exchange_category Tablet
Failed to import it_exchange_category Computer Mouse
Media “slide1_bg.jpg” already exists.
Media “balloon2.png” already exists.
Media “balloon.png” already exists.
Media “slide2_bg2.jpg” already exists.
Media “paraglider.png” already exists.
Media “slide3_BG.jpg” already exists.
Media “plane.png” already exists.
Media “photodune-1860048-professional-team-xs.jpg” already exists.
Media “photodune-358775-team-xs.jpg” already exists.
Media “blog2 (1)” already exists.
Media “blog1 (1)” already exists.
Media “item_0002_8765284634_b5d78eca5e_b” already exists.
Media “item_0005_8909979225_3c9f1b23c3_h” already exists.
Media “item_0007_9659969185_195bc4225b_h” already exists.
Media “item_0004_9573354587_8636f7b080_h” already exists.
Media “item_0001_9435123826_e89b552f7a_b” already exists.
Media “item_0003_9411943299_9af4a6d428_b” already exists.
Media “item_0000_9814949385_07c193c89c_h” already exists.
Media “item_0006_9913190443_cb17108aad_h-e1393843274377” already exists.
Media “breadcrumbs-bar-bg” already exists.
Media “tf” already exists.
Media “ad” already exists.
Media “aj” already exists.
Media “cc” already exists.
Media “gr” already exists.
Media “item_0000_Layer-4” already exists.
Media “item_0001_Layer-3” already exists.
Media “item_0002_Layer-2” already exists.
Media “item_0003_Layer-1” already exists.
Media “map-pointer” already exists.
Media “pd” already exists.
Media “people” already exists.
Media “picjumbo-pen-diary” already exists.
Media “image1” already exists.
Media “image2” already exists.
Media “image3” already exists.
Media “partners” already exists.
Media “parallax2” already exists.
Media “gadgets” already exists.
Media “image4” already exists.
Media “parallax3” already exists.
Media “gadgets2” already exists.
Media “icon1” already exists.
