KB-1285 Excel Tools throws "java.lang.NoClassDefFoundError" in the application server log

Symptoms

Data fails to be exported to Excel using the shared component, “Download Data Subset”.

An error is seen in the log that indicates a class is missing, despite the plugin previously working. An error similar to the following is seen in the server log:

[[ACTIVE] ExecuteThread: '29' for queue: 'weblogic.kernel.Default (self-tuning)'] ERROR com.appiancorp.ra.workpoller.WorkItemListener - The following exception occurred while attempting to complete work item [(WorkId: 10, WorkType: [ExpressionGroupRequest: expressionGroupId=442, [ExpressionGroup as '1234567' context [Task:123]: isFileCorrect:readexcelsheet(pv!excelDocument_doc,0,1,1).result.values[1]="Instructions" with values
...
Caused by: javax.ejb.EJBException: EJB Exception: : java.lang.NoClassDefFoundError: Could not initialize class org.apache.poi.openxml4j.opc.internal.marshallers.ZipPackagePropertiesMarshaller

Cause

The shared component, “Excel Tools”, contains a newer version of the same class referenced by “Download Data Subset”, causing a class loader conflict.

Action

1. Install the newer shared component, “Excel Tools” as it contains the same functions and supersedes “Download Data Subset”.
   1. When deploying the new plugin, please delete all old versions of the ExportableDataSubset CDT AND update your model to point to the new version {urn:com:appian:ps:excel:types}ExportableDataSubset.
2. Remove “Download Data Subset” from the environment after installing Excel Tools.

Affected Versions

This article applies to all versions of Appian.