Problem
Error in rxCall("RxGetInfo", params) :
System Error: Failed to open file "/user/training1/QdotNoTransNoNA/train/data/_1.xdfd". Check to ensure that the filename and path are valid.
The command used was:
mycXDF <- RxXdfData('/user/training1/QdotNoTransNoNA/train/', fileSystem=hdfs)
Solution
The trailing "/" at the end of the command causes ScaleR to look to a non-existent sub-folder.  Remove the trailing /
