I am not exactly sure why this sometimes happens (I think I have seen it twice here). For me, the solution was to select the offending audio clip, and then “Bounce Selection”. The bounced replacement can then be modified 
.
I am not exactly sure why this sometimes happens (I think I have seen it twice here). For me, the solution was to select the offending audio clip, and then “Bounce Selection”. The bounced replacement can then be modified .