Cause
You have placed a conduit to which you have assigned a part with fixed function templates (device) in the schematic. When placing the conduit you have however used less functions (conduit connections) than the corresponding part has. For example, you have selected a part for the placed conduit that contains 4 conduit connections of which you only use 3 in the schematic.
Solution
Possibility 1
Select a conduit part with a suitable function template assignment (number of conduit connections).
Possibility 2
Reduce the function template assignment (number of conduit connections) for the selected part in the parts management. To do so select the menu items Utilities > Parts > Management, and select the Function templates tab in the Parts management dialog. In the table, highlight the function templates you want to remove and click 
(delete). Copy the changed setting into the parts management. Then place the conduit as a device once more in the schematic.
Then start a new check run.
Note:
Whether this message is issued depends on the Minimize unused functions and Number of unused functions settings. You move to the settings by firstly opening the Properties dialog of the device, bringing the Part tab to the front and clicking the [Device selection] button. Subsequently click [Settings] in the Device selection dialog and use it to open the Settings: Device selection dialog with the setting options previously stated. You set the number of functions not used in the device (reserve functions) that the part should make available by using the Number of unused functions setting. The number can only be set if you have selected the Minimize unused functions check box setting.
If the Number of unused functions setting is set to "0", all the unused templates are identified as error(s).