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Ensure that you have successfully installed ver 4.0.8 or later on-premise
Export your data into an XML file according to the short documentation on the screencopy below:
Import your data into Traffic-Lights for Jira Cloud by selecting this XML file from your local file system and click on “import”.
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On-prem field types
The importer is capable to import my “Traffic-Lights for Jira” (Server/Data Center) as well as the data of “Simple Traffic Lights for Jira” by t2consult, not offering a Cloud solution currently.