When I created issue #42 and tried to assign it as a blocker to issue #33. An error came up saying that issue #42 was not in the same project as issue #33 and couldn't be assigned as a blocker.
It seems this shouldn't be a blocker.
I believe Troy wishes to relate a task outside of the current project (as blocking) I do not think this is a capability that we can add to Redmine, so I have instructed Troy to simply comment on the ticket and change the status to "On Hold / Waiting" amd reassign the ticket to whomever owns the blocking task or issue -- Hope this makes sense.
I am going to close this ticket as unresolved as the feature requested is not available and the instructions given represent a workaround.