It looks like that multi-line tooltip does not work on the latest version.
note over Foo, Bar
Yet another link to [[
http://www.google.com]] as demo.
You can also [[
http://www.yahoo.fr specify a text]] for the link.
And even [[
http://www.yahoo.fr{This \n is a \n tooltip} add a tooltip]] to the link.
end note
Bob -> Alice : hello
note over Bob, Alice: [[
http://yahoo.com{hello\nworld}hello]]note
Thanks