Yes, this was the problem. I fixed it by adding some devices just to "reach" the correct letter (H).

Thanks a lot again !

I load my saved mix (sgp file) on a different computer, than i created this mix, (my laptop) in order to continue editing there, and no tracks are shown in this file. Note that the tracks source (external hard disk) is the same on both computers. Am i doing something wrong? (App. Version 2.471) Than...