If you start importing and then experience an interruption in internet access, you will need to reinitialize the import process, but previously downloaded files will still be downloaded. We are looking at improving the resuming behavior for this process in the next version of Kolibri.
In your current screen shot, it appears that the files in the Math folder have not imported. Because the KA Math folder is quite larger, we suggest importing it in smaller pieces by clicking into the Math folder and selecting a few sub-folders to import at a time.
Let me know if this helps.