This is the second or third time I've seen this error after doing an offline bounce. The bounced file wouldn't automatically be imported to a new track as instructed, but instead I got this message.
I use PT Ultimate, the hidden tracks in the picture are inactive. I'm not even close to the maximum available tracks.
Using 2019.6 on MacOS 10.14.5.
Most bounces work fine, but some randomly do not.