Error executing Association Rule Learner (Borgelt)

Hi collegues,

I have noticed that sometimes when I run the test workflow for several times the execution of Association Rule Learner (Borgelt) is interrupted and the rules generation process fails.

This is the specific console log error:

ERROR Association Rule Learner (Borgelt) 0:201:163  External executable failed (error code 137): /home/ubuntu/knime_3.3.1/plugins/org.knime.ext.itemset_3.3.0.v201612012034/resources/executables/linux/x86_64/apriori - find frequent item sets with the apriori algorithm
version 6.22 (2016.04.09)        (c) 1996-2016   Christian Borgelt
reading /tmp/knime_basket_products98407/isInput6505112308525688222.txt ... [374034 item(s), 669527 transaction(s)] done [0.28s].
building transaction tree ... [255060 node(s)] done [0.05s].
checking subsets of size 1

This problem looks quite strange, since i didin't changed anything in the workflow configuraton.

I have just reset all nodes and relaunch it. 

Has someone of you an idea of what could be the problem?

-Giulio