Liferay Archive (LAR) files are not portable across versions of the Liferay Portal. You cannot import a LAR file created in an earlier version of Liferay into a newer version.
LAR files allow you to export all of your Discovery Framework application pages to a single file. This file can be exported from one server running Liferay and imported into another running the same version of Liferay. This feature is very useful when you want to back up an application or move it from a development to a production environment.
However, LAR files are not portable across versions of the Liferay Portal. As a result, you cannot import a LAR file exported from a pre-1.4 version of the Discovery Framework into Discovery Framework 1.4.
In between versions 1.3.x and 1.4 of the Discovery Framework, an important patch was applied to the underlying Liferay Portal. Any LAR file created before the patch was applied cannot be imported to an environment with the patch applied. Similarly, any LAR file created after the patch is applied cannot be imported in an un-patched environment. As a result, you cannot import a LAR file exported from Discovery Framework 1.3.x (or earlier) into Discovery Framework 1.4.
The recommended approach to maintain your configuration across upgrades is to use the same underlying database.