Association with gff3 files seems unhelpful

Jalview associates itself with gff3 files, however doesn't seem to do anything meaningful with them when double-clicked. Regardless of the content of the gff file, the window opens with the content shown in the attached image, with the sequence 'THISAPLACEHOLDER'.

The same results occur if the appropriate reference sequence is already open in jalview, rather than features being applied to the sequence.

Unless jalview is going to do something sensible with gff files when double-clicked, it should not associate itself with them, so they will instead open in something like a text editor.