ESXI OVA/OVF import from other hypervisors

Hey everyone. I'm currently trying to import an OVA file into a 6.7 ESXi host, however I'm getting the following error message. Unsupported element 'StorageItem'.

The OVA file in question was created using Virtualbox. I'm currently trying to migrate some of our VMs onto this ESXi host and were wondering it is possible to import and export OVA/OVF files when they are created using separate virtualisation platforms. Is there a specific process to follow to achieve this? Any information in regards to this issue would be appreciated.

Thanks.