Some things that come to mind:
The asset is named DAX_2017_06_1m, and you mentioned DAX_2017_06_1m.bar
That looks wierd, although I'm not familiar with the .bar format.
Why did you put year (and month?) in the asset name?

Atleast my 1 minute data is in .t6 format, and files are divided per year only.
So for EUR/USD, files are named EUR/USD_2016.t6, EUR/USD_2017.t6 etc.

Perhaps nothing is wrong with using the .bar, but I would at least try changing the asset name to something like just DAX, and the file to DAX_2017.bar