Hello
When I play my DK, shortly after using Blood Tap ability
I start receiving "Not enough runes" message in the center of the screen when I want to use some more ablities, although the ablities on my bars are active and enabled, showing I have the runes to use them.Immediately activates a Blood Rune and converts it into a Death Rune for the next 20 sec. Death Runes count as a Blood, Frost or Unholy Rune.
I also think I can get a screenshot with that if it helps, on a target dummy.