Internal form mapping is undefined for "Step1"

Hi all,
I’m a newbie in bonitaSoft;
I’m trying to build a simple process, and a form for the the pool and the human task: “clicked on the pool → application → PageFlow → Add” and “clicked on the human Task → application → PageFlow → Add” but I’m facing this error:

Internal form mapping is undefined for Étape1. org.bonitasoft.studio.designer.core.bar.FormMappingBarResourceProvider.isValid(FormMappingBarResourceProvider.java:147) org.bonitasoft.studio.designer.core.bar.FormMappingBarResourceProvider.addFormMapping(FormMappingBarResourceProvider.java:83) org.bonitasoft.studio.designer.core.bar.FormMappingBarResourceProvider.newFormMappingModel(FormMappingBarResourceProvider.java:76) org.bonitasoft.studio.designer.core.bar.FormMappingBarResourceProvider.addResourcesForConfiguration(FormMappingBarResourceProvider.java:68) org.bonitasoft.studio.engine.export.BarExporter.createBusinessArchive(BarExporter.java:117) org.bonitasoft.studio.engine.export.BarExporter.createBusinessArchive(BarExporter.java:91) org.bonitasoft.studio.engine.export.BarExporter.createBusinessArchive(BarExporter.java:165) org.bonitasoft.studio.engine.operation.ExportBarOperation.exportBar(ExportBarOperation.java:118) org.bonitasoft.studio.engine.operation.ExportBarOperation.run(ExportBarOperation.java:106) org.bonitasoft.studio.engine.ui.wizard.ExportBarWizardPage$7.run(ExportBarWizardPage.java:405) org.eclipse.jface.operation.ModalContext$ModalContextThread.run(ModalContext.java:122)

Thank you for your suggestions.
Regards

Hi,

By application, you probably mean “6.x Application”.
This allows you to design forms with our former designer. But with version 7, you should go in “execution” > “(instantiation) form” instead to use the new designer.
However, if you want to stick with the old designer, you need to check the “6.x” option in this same section (“execution” > “(instantiation) form”). This is the reason why you get this error.

Here is a a documentation page that explains it all:
http://documentation.bonitasoft.com/page-and-form-development-overview

it works just fine, Thank you for your answer,