Trimble Quadri Help
Conversion rules have settings specifying from which source(s) and which destination(s) they are valid. If you don't see any matching conversion rules when you try to select a conversion rule during import, it means there is no match for your current source and destination format.
If you open the Conversion Rules editor (available from the "Insert" ribbon), you can see all available conversion rules. If one exists for your source and destination format, you can easily make a copy and put in your User Defined Conversion Rules directory. Then select it and press "Properties" to enter the dialog described in: Conversion Rules. Change the settings so it matches your current situation.
When you now try to select conversion rule, you should see this rule under "User defined conversion rules".
Note the description that no conversion rule for main version X of a Feature Catalog works for any Feature Catalog with another main version number, even if the setting "Backward" or "Both" is used!