Are you planning to to a newer version, or do you need to fix a specific error in an old 4.0.1 environment?
If you use the NetBeans IDE, you can find the plugin version (NBM files) on the Jaspersoft Community Knowledge Base .
iReport Designer v4.0.1 Release Notes - Jaspersoft Community jaspersoft ireport designer 4.0.1 download
To ensure the designer runs correctly on modern systems, follow these requirements:
To download the corresponding jasperreports-4.0.1.jar for your Java project, visit the JasperReports Archive . Key Features of Version 4.0.1 Are you planning to to a newer version,
Improved CSV datasource support and new namespace-aware query executors.
Resolved common copy-paste issues for variables and fixed the "Bring to Front/Send to Back" UI commands. Key Features of Version 4
The primary source for the installer is the iReport Project on SourceForge, which includes the Windows installer ( .exe ), Mac DMGs, and Linux binaries ( .tar.gz ).