Assume company X bought company Y, both using Jira servers. We want to merge these two servers where there is no loss for custom fields/boards/sprints/history etc. There are two plugins that I know of about this issue, project configurator and configuration manager. However, we get some errors different than each other.
I also tried having backup and deploying to the other one, also exporting to/importing from excel or csv files don't work since they don't keep history data etc.
Is there any other way to merge two servers with all the projects & issues & boards etc. where there will be no loss of any data?