null pointer exceptions with cpn inhibitor arcs when verifying

[Lena Ernstsen]

When verifying a colored net with inhibitor arcs, an error occurs during verification resulting in a nullpointer exception.

The options that are sent to the engine:
/Users/lenasaid/Downloads/verifypn-osx64 --k-bound 6 --search-strategy BestFS --reduction 1 --write-reduced /var/folders/q_/qn8ll2bd1yj99s93s_yj9v7r0000gp/T/reduced-2251108571346496018.pnml --ctl-algorithm czero --xml-queries 1 /var/folders/q_/qn8ll2bd1yj99s93s_yj9v7r0000gp/T/verifyta2960963259852330351.xml /var/folders/q_/qn8ll2bd1yj99s93s_yj9v7r0000gp/T/verifyta4777929778187286163.xml

The tapn net and files sent to the engine is attached