Media upload path issue


I've got a multisite up & running with a couple of sites working OK, but I can't currently upload media to anything other than the main network site.

I believe the issue is to do with the upload path because its trying to upload to:


But the path should be:


One possible reason for this error is that the network site was migrated from a cloud server (tsohost) to my new VPS server... though I can't be sure this is the root cause!

Is this fixable?