FTP Adapter error: SLDAccess

Hello everyone!

When XI picks up an XML using the FTP adapter (sender), I get this error message:

<b><i>Error: com.sap.aii.af.ra.ms.api.ConfigException: Some of the IS access information is not available. SLDAcess property may be set to true, but SLD is not available.</i></b>

in the Comm. Channel monitoring. No message is processed in the Integration Engine.

Would anyone know what could be causing this error?