jasper part load too much of time in our system. WHY?
The last version of the iReport NetBeans plugin was released over 5 years ago and there will be no more releases of it. I would be surprised if it worked with current versions of NetBeans.
All later development of a JasperReports desktop designer has been focused on Jaspersoft Studio, which is Eclipse based. Studio can be placed in a compatibility mode with earlier versions of JasperReports, back to version 3.1.0.