Cannot connect to instance. That subarea has expired

I entered a vaal side area, but decided to complete it later and returned to map area. Then I got a abyssal depth, completed that and returned to the vaal side area.

Then I got this error, when I tried to enter it again:
"Cannot connect to instance. That subarea has expired because it is no longer the most recent child instance for this area."

Bug reference number 4.154.741.573