- Enable the console. There are several guides to do this out there. Most of them can be found here.
- Use the command "runscript zz_dae_debug" - this should bring up a menu of options. You will not to able to see the command as you type it.
- Click on Plot Jump -> core/critical path -> investigate -> circle plots -> wayward son -> more options -> the cave on the wounded coast
- This will set the quest to the wounded coast stage and teleport you to the cave entrance
- Head on in and finish the quest.
Hopefully this works for people. On a related note, these two posts have gotten me more hits than ever before. This means the problem must be pretty common, hopefully bioware will put out a fix soon.
I don't see why this wouldn't work for other similar bugs: give it a go and explore the menu. There also maybe other scripts for various DLC