How many parallel tasks do you have? And check values for next setup fields:
QVEMC -> System -> Distribution Services -> QDS -> Advanced -> Max number of simultaneous QlikView engines for distribution
QVEMC -> System -> Distribution Services -> QDS -> Advanced -> Max number of simultaneous QlikView engines for administration
I do not have the "Distribution Service" in my QlikView Server. The distribution of applications is done through the QVS. Inside the QVS, there is that same option and it was scheduled:
Max concurrent reloads: 2
How many parallel tasks do you have?
Theoretically no, but the reload time can extend and generate a competitive application.
Maybe some application error has made and passed that value of max concurrent reloads. Moved up to fourth and shortens the timeout to reload the applications scheduled to reload.
Sorry for my bad english :)