It's taken me quite some time to get the deployment steps for the Public Preview of D365 for Marketing to work with an exisiting UK tenant in the EMEA (i.e. crm4. data centre). The problem seemed to be that the Preview Setup wizard tried to use the new UK (i.e. crm11.) data centre instead of EMEA (crm4.). After much experimentation (changing crm11 to crm4 in URLs) and trying a few different values for seemingly country specific parameters I was finally able to get the setup wizard to complete and (fingers crossed) it is now deploying a preview instance to my EMEA (crm4.) tenant however I'm not sure exactly which of the steps I took were necessary to get this to work.
I understand this is a known issue and was supposed to be being fixed but it doesn't appear to be working at the moment.
Please can you post a news item for UK Preview Participants so they know how to work arround this problem.