Цитата:
04-21/16:20:01 ERROR [pool-2-thread-5] Calculator - error while calculating contract 18 and service 5
java.lang.NullPointerException
at java.util.ArrayList.addAll(Unknown Source)
at bitel.billing.server.npay.Calculator.executeTask(Calculator.java:367)
at bitel.billing.server.task.TaskBase.run(TaskBase.java:50)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Из-за чего может возникать?