how to reproduce

• create a page from the demo https://demo.ametys.org/nightly-intranet-cms/www/index.html
• create content
• insert a first form with an email field and a validated button
• insert another form with an email field and a validated button
• Enable acknowledgment of receipt on both forms
• go to the preview
• complete the second form
  An "oups" appears and there is this error in the back office admin:

  Caused by: java.lang.NullPointerException: Cannot invoke "org.ametys.plugins.forms.content.data.FieldValue.getValue()" because "receiptEntry" is null
  at org.ametys.plugins.forms.content.processing.ProcessFormHelper#_sendReceiptEmail:1664
  at org.ametys.plugins.forms.content.processing.ProcessFormHelper#_sendEmails:1578
  at org.ametys.plugins.forms.content.processing.ProcessFormHelper#processForm:275
  at org.ametys.plugins.forms.content.processing.ProcessFormAction#act:131
  at org.apache.cocoon.components.treeprocessor.sitemap.ActTypeNode#invoke:125
  at org.apache.cocoon.components.treeprocessor.AbstractParentProcessingNode#invokeNodes:47
  at org.apache.cocoon.components.treeprocessor.sitemap.MatchNode#invoke:108
  at org.apache.cocoon.components.treeprocessor.AbstractParentProcessingNode#invokeNodes:69
  at org.apache.cocoon.components.treeprocessor.sitemap.PipelineNode#invoke:143
  at org.apache.cocoon.components.treeprocessor.AbstractParentProcessingNode#invokeNodes:69
  at org.apache.cocoon.components.treeprocessor.sitemap.PipelinesNode#invoke:93
  at org.apache.cocoon.components.treeprocessor.ConcreteTreeProcessor#process:236
  at org.apache.cocoon.components.treeprocessor.ConcreteTreeProcessor#buildPipeline:194
  at org.apache.cocoon.components.treeprocessor.TreeProcessor#buildPipeline:267
  at org.apache.cocoon.components.treeprocessor.sitemap.MountNode#invoke:111
  ... 135 more