(BB 2015 & Real Band build 417. Win 8))
As I understand the manual to merge I highlight my four tracks (mono), select destination track in menu box, decide to keep fx etc. However on OK I am told my destination track has data on it and therefore cannot be used. It hasn't. It does have straight blue lines though.
In fact all 48 tracks are seen as having data on them as I cannot use 'insert blank track command either'

Am I configuring 'new file' incorrectly in some way?