Project Configurator for Jira Server and DC

java.lang.NumberFormatException - Null Within SpringImportHandler

Problem: This error occurs while importing Sprint data as can be seen at the top of the error trace:

Data import failed with exception: null
java.lang.NumberFormatException: null
at java.lang.Long.parseLong(
at java.lang.Long.valueOf(
at com.atlassian.greenhopper.imports.SprintImportHandler.endTable(

Solution: The Jira knowledge base article, Project Import fails with Unexpected import failure, describes this issue, points to the bug ticket with the root cause and recommends how to fix it.