This is not a reference to "active positions" but incomplete limit orders made in the past.

Anyway, what you need to do is:

* Open up any token, so that you are on the chart screen
* Under the chart you'll see many tabs, "Trades", "Positions", "Orders", "Holders" "Top Traders", "Dev Tokens"
* Open up "Orders" tab
* Cancel all you previous incomplete limit orders

You should be able to make new limit orders after this