Steps to reproduce in beta:

As a user with sysop permissions

1. Click on 'Collections' in the main menu.
2. Click on 'Watchlist' on the loaded 'Collections' page under the 'My collections' tab. (Btw, you can click on any other collection too.)
3. Bring your mouse over the '-' icon enclosed in a black circle and you'll see the message: "Do you want to hide list "$1" by $2?", where $1 and $2 are supposed to be some texts.

See the attached screenshot below:

Also notice the positioning of the icon. It's well outside the container. It should not be pushed that far to the right. It should align with the right of the collection list.