Well 2015 is pretty old, the menu paths and options would be different than more current versions

If you Hover the mouse over the Track icon, a popup should appear, in that popup, does the Events item show a number?
If it is greater than zero, the track has data.
As mentioned; erase the data and try again. Or, if comfortable simply 'Erase Track' (which should give you a new blank track).

Or maybe try merging those tracks to a Wav file, and then importing the Wav file to a blank track, just a thought as a workaround. Like I said 2015 is pretty old and I don't recall this issue, maybe because I am pretty old too.


Make your sound your own!
.. I do not work here, but the benefits are still awesome