ERROR: Exception in thread "main" java.lang.NumberFormatException: null

[wendysyn89]

hi,

I received this error when parse the sentences:

Performing frame-semantic parsing.
input-file:/tmp/semafor.1v1uWbbdQ9/conll
output-file:/home/wendy/semafor/bin/review_gold_output.txt
model-dir:/home/wendy/models/semafor_malt_model_20121129
numthreads:

Exception in thread "main" java.lang.NumberFormatException: null
at java.lang.Integer.parseInt(Integer.java:542)
at java.lang.Integer.parseInt(Integer.java:615)
at edu.cmu.cs.lti.ark.util.CommandLineOptions$IntOption.set(CommandLineOptions.java:187)
at edu.cmu.cs.lti.ark.util.CommandLineOptions.init(CommandLineOptions.java:267)
at edu.cmu.cs.lti.ark.fn.utils.FNModelOptions.(FNModelOptions.java:40)
at edu.cmu.cs.lti.ark.fn.utils.FNModelOptions.(FNModelOptions.java:36)
at edu.cmu.cs.lti.ark.fn.Semafor.main(Semafor.java:94)

Anyone know how to solve this?

Many thanks.