Hi Calixte,
I haven’t fully resolved the issue as yet but I have discovered why I was getting the error message. When I create my inital audio transition using the short cut for my favourite audi transition (alt+cmd+t), I am not able to copy the effect by alt dragging it to other clips – as per my original post.
However if I add the initial transition by going straight to the effects tab, rather than using the shortcut, I can manipulate the transition and copy it to other clips withoput any problems.
I hope this helps.
Cheers
Andy