This is a fairly minor bug. In the attached picture you can see that in the list of cards contained in the deck for LucasMcL, it says "-1 Death Carts". I had 0 death carts in my deck and this shouldn't be listed at all.
I think I know how this may have happened. I played an Overlord and played it as a Death Cart. My Overlord was then immediately trashed because I chose not to trash another action card. The game must have mistakenly decremented my total count of Death Carts from 0 to -1 in that moment.
The game was #15286219 on Tokyo.
I was playing in the chrome browser on Ubuntu 17.10.
I think I know how this may have happened. I played an Overlord and played it as a Death Cart. My Overlord was then immediately trashed because I chose not to trash another action card. The game must have mistakenly decremented my total count of Death Carts from 0 to -1 in that moment.
The game was #15286219 on Tokyo.
I was playing in the chrome browser on Ubuntu 17.10.