It is strongly recommended that you install the main Indigo application before installing any exporters, so that they can find the existing Indigo installation and link to it automatically. (This is normally done for you by the Indigo installer since version 3.2.)
It's possible to have a mismatch between the installed Indigo version and the exporter version; this can result in Indigo displaying an error message about unknown data in the scene file. In this case updating to the latest versions of both will generally resolve the issue.
For more information about the various Indigo exporters, please consult the corresponding manual or our Exporters forum.