Cheers fella I have put this in the client support too
Very strange. So when i tested this earlier in legacy combat it would select the spell but not cast it on the item. In EoC it would expand the action bar but it didn't get stuck doing so like you said it did. It then dragged the skilling spells page down to the action bar instead of clicking it and dragging the spell to the action bar.
I just tested it again in both EoC and it casts the spell just fine... EoC still has the dragging of the skilling spells page issue, but if you move the spell onto the action bar yourself it works fine.
Okay so i finally replicated the expanding action bar issue, sort of... It toggled it once or twice and then it was fine. Upon further debugging i found that once in a blue moon ActionBar.isExpanded returns false even though it's expanded, and then it goes back to returning true again. This is a client issue.
@Cloud
Until that's fixed i'll add in a work around that just repeatedly checks if it's open for a small period of time. I've also fixed the issue with adding the spell to the action bar, expect a release shortly.
starts and gets stuck on trying to activate high alch :'(