[galaxy-dev] none mapping is not currently available!

Hi all, I tried to run a small workflow on Galaxy, which basically attempts to establish a correlation between the Chip-Chip, Polymerase binding and Dnase Hypersensitivity data. The input would be these 3 files, I am initially performing a liftover on the Chip-Chip data to convert from hg18 to hg19 and then using the output to establish the correlation. Here, you can see a screenshot of the pipeline here: As I am running this workflow, the desired output isn't obtained and the following error: "none mapping is not currently available" is obtained. Can someone please explain what this means, and what am I to do after this! Thanks a lot people!! -Sameer