The latest version of NVivo was released in March 2020, it supersedes NVivo 12.
Projects from the latest version of NVivo cannot be opened in older versions of NVivo such as NVivo 12 or NVivo 11. That means if you have done work in new NVivo - Windows or NVivo - Mac project, you will not be able to open it in an older copy/version of NVivo that you might own.
You are using the latest version of NVivo and still receive the error?
In January 2022 an update to NVivo 1.6 was released, which updated the database version installed with NVivo. This means that projects created in release 1.6 (and following) cannot be opened in any earlier version. So please check for updates (NVivo start screen - File – Product info – check for updates) and make sure that everyone in the team has the latest update installed. This should solve the issue:
However, if you are an NVivo 12 user and you have opened your project in the new NVivo, there is a limited workaround that allows you to re-open your project in NVivo 12. You may be able to export your project data (with some limitations) to REFI-QDA open exchange format (more information about this is found in How can I import/export a project from/to other QDA programs such as Atlas,ti, maxQDA, Dedoose etc?) You can then import this data into NVivo 12 format.
Note: NVivo Support team is unable to convert a project so it can be opened in older versions of NVivo.