XCP has a spin-off project called Kronos, where we're porting the XenAPI toolstack to run on Debian. This version of xapi does not contain the license_params:sku_marketing_name database key.
When OXM connects to a host, it outputs some debug information. This debug information includes the sku_marketing_name key. Because it doesn't do any existence checks, this call throws an exception and OXM fails to connect to the host.
Since this is just debug information, and isn't used later on, I just removed the lookup of sku_marketing_name. This might not be the best way to do this, since we could just catch the exception and proceed, but it was the quickest way I could get OXM working with Kronos.