NPE when evaluating a DMN decision table with multiple outputs and one of the outputs has wrong type

When I have a decision table with hit policy Priority and multiple outputs and I change one of the outputs in a rule to a wrong type, the evaluation ends with NullPointerException.

E.g. having output entry like this:
<outputEntry id="_7f03803d-2636-40ab-8346-7fd7f38ab695-3">
<text>1</text>
</outputEntry>

I will provide PR with reproducer for this.