When you attempt to open a Manager.io business file in an older version, the program might refuse to open it because of version incompatibility.
Newer versions of Manager.io can always open businesses created in older versions of the program, but not the other way around.
This means if you are transferring business data between computers or editions, make sure you are transferring to an equal or newer version only.
For example, importing a Manager.io business to Cloud Edition always works because Cloud Edition is always running on the latest version automatically.
However, if you are importing a business from Cloud Edition to Desktop Edition, you might need to upgrade to the latest version of Desktop Edition first by downloading it from https://www.manager.io/download
Similarly, if you are importing a business to Server Edition, you might need to upgrade to the latest version of Server Edition by downloading it from https://www.manager.io/server-edition