I launch RB 6.0.3
The Update Manager appears asking if I want to update to 6.0.4
I click Start
I get prompted for my Mac password
The 'Currently downloading the update package.' dialog appears.
The dialog progress bar moves in tiny increments every minute but after 10mins has barely made any progress (normally takes seconds to download the update).
I can get around it by manually deleting the previous RB version and directly downloading the new file myself. Maybe there is a corrupt file on my machine that is confusing the update manager?