When migrating from JIRA Cloud, the following error is being thrown in the UI:

Steps to reproduce:

1. Generate and download a Backup from a Cloud instance.
2. Install a clean instance of JIRA Server latest version.
3. During the setup, click to import existing data, and import the backup from JIRA Cloud.
4. The error will be thrown.

Workaround:

1. Uncompress the Backup.zip originated from JIRA Cloud.
2. Open the entities.xml file.
3. Search for the JIRA Cloud build number (64005) which should return results like the following:

       </OSPropertyString>
       <OSPropertyString id="1" value="64005"/>
   

           </OSPropertyString>
       <OSPropertyString id="11130" value="64005"/>
       <OSPropertyString id="11131" value="1.1.5"/>
   

4. Change the value from 64005 to 6337:

       </OSPropertyString>
       <OSPropertyString id="1" value="6337"/>
   

       </OSPropertyString>
       <OSPropertyString id="11130" value="6337"/>
       <OSPropertyString id="11131" value="1.1.5"/>
   

5. Compress the entities.xml and activeobjects.xml again, and import the .zip to the clean JIRA instance.