https://community.qlik.com/t5/Archived-Discussions/Dataset-Head-Sample-preview-error/m-p/2402634#M76 <P>Seen https://stackoverflow.com/questions/35963285/org-apache-avro-unresolvedunionexception-not-in-union-long-null but doesn't really help narrow issue down...</P> Fri, 06 Nov 2020 00:07:50 GMT andrew_bates 2020-11-06T00:07:50Z https://community.qlik.com/t5/Archived-Discussions/Dataset-Head-Sample-preview-error/m-p/2402633#M75 <P>Hi we are trying to use a Kafka connection to create a dataset and selecting JSON format:</P><P></P><P></P><P> <span class="lia-inline-image-display-wrapper" image-alt="0693p00000AGsi6AAD.png"><img src="https://community.qlik.com/t5/image/serverpage/image-id/127724i14BE8D19496E9D93/image-size/large?v=v2&amp;px=999" role="button" title="0693p00000AGsi6AAD.png" alt="0693p00000AGsi6AAD.png" /></span></P><P></P><P></P><P>However when Pipeline Designer tries to create a preview I am getting the following error:</P><P></P><P></P><P><span class="lia-inline-image-display-wrapper" image-alt="0693p00000AGsOqAAL.png"><img src="https://community.qlik.com/t5/image/serverpage/image-id/130268iE0D5AE21391D8A4E/image-size/large?v=v2&amp;px=999" role="button" title="0693p00000AGsOqAAL.png" alt="0693p00000AGsOqAAL.png" /></span></P><P>We would like to understand what the "Not in union" error means and what I need to do to resolve it?</P> Thu, 08 May 2025 17:40:29 GMT https://community.qlik.com/t5/Archived-Discussions/Dataset-Head-Sample-preview-error/m-p/2402633#M75 andrew_bates 2025-05-08T17:40:29Z https://community.qlik.com/t5/Archived-Discussions/Dataset-Head-Sample-preview-error/m-p/2402634#M76 <P>Seen https://stackoverflow.com/questions/35963285/org-apache-avro-unresolvedunionexception-not-in-union-long-null but doesn't really help narrow issue down...</P> Fri, 06 Nov 2020 00:07:50 GMT https://community.qlik.com/t5/Archived-Discussions/Dataset-Head-Sample-preview-error/m-p/2402634#M76 andrew_bates 2020-11-06T00:07:50Z