Selection tools greyed out in Multitrack

[Petter27503227u2fw]

  

I am currently working on a project in Audition on a Mac running OS12.6. I have been using Audition daily over the last couple of months, but today while is was working my Marquee selection suddenly stopped working and I cant seem to get it back up and running. I have tried resetting my Mac and its PRAM, and also factory set Audition but I still can't seem to get it up and working as it should. Is there anything im doing wrong? 

[SteveG_AudioMasters_]

Can't see anything wrong there - but the Marquee tool only works on the spectral display, and the spectral display is only available in Waveform view. You appear to be in Multitrack...