Research not working

[Supamand]

I had this happen to. I had all right requirements, but the skill would not stop training. I had to remove all skills, then start training some lvl 1 skill then cancel the level one skill and set up my original skull that I was intending to train. Unfortunately I lost over 24 hours
And unfortunately I didn't send a bug report when it happened.

[VanderLegion]

So I figured out what the problem is with the research queue:
Say you have advanced shipyards currently researching so you're queue looks like:
Advanced Shipyards Tier 1
xx% complete / Time Left hh:mm:ss Rank y/9

When you add a new item, say advanced materials collection, it should look like
Advanced Shipyards Tier 1
xx% complete / Time Left hh:mm:ss Rank y/9

Advanced Materials Collection Tier 1
Training Time 12:00:00 Queue: 1 Rank y/9

The problem occurs if you tap too many times on Advanced Materials Collection when you go to add it in the queue. If you tap it in quick succession, it'll add it in position 1, then instead of removing it when you tap again (again, if you tap quickly), it'll try to add it to the queue again, since there's already something in Queue: 1, it'll put it in Queue: 2, and since it's the same research item, the one in Queue 1 disappears, so you end up with:
Advanced Shipyards Tier 1
xx% complete / Time Left hh:mm:ss Rank y/9

Advanced Materials Collection Tier 1
Training Time 12:00:00 Queue: 2 Rank y/9

Note that this leaves you with a currently researching item and an item queued to position 2, but nothing in position 1. When the advanced shipyards finishes researching, it goes to start the next item but there's nothing queued up in position 1, so nothing starts researching. The Advanced materials collection never starts because it's in position 2, so it's waiting for the item in position 1 to start researching and the position to get bumped down. You can end up with things in higher positions as well. If you tap several times, you might end up with a current item and a Queue: 3 with nothing in Queue 1 or 2. When you get items in higher positions like that, you might have to remove the same item several times to get it out of the queue completely, then readd it to get it back in Queue: 1 so it works right.

Edit: For the devs - hopefully this is enough for you to find where the issue is and get it fixed in a future build as well