Hookmark get a Trello card’s url from Trello ->Edit->Copy Current URL, with keyboard shortcut option+command+c. Could you please check if you can copy the URL on your mac?
Could you please copy and paste the following script into Hookmark preferences window->Scripts->Trello->Get Address, and click on Save button? See if it works?
Get Address Script
set the clipboard to ""
delay 0.1
tell application "System Events" to tell process "Trello"
keystroke "c" using {option down, command down}
delay 0.1
repeat 20 times -- poll clipboard for ~2.5 seconds. Sometimes set x to teh clipboard throws exception
try
set theURL to the clipboard
if theURL is not equal to "" then
exit repeat
end if
keystroke "c" using {option down, command down}
end try
delay 0.1
end repeat
set theTitle to name of window 1
set AppleScript's text item delimiters to {"/"}
end tell
set prevTIDs to text item delimiters of AppleScript
set text item delimiters of AppleScript to "/"
set reverseUrl to "" & reverse of text items of theURL
set text item delimiters of AppleScript to prevTIDs
set theOffset to offset of "/" in reverseUrl
if result is not 0 then
set theOffset to (count (reverseUrl)) - theOffset
set theURL to text 1 through theOffset of theURL
set theURL to text 6 thru -1 of theURL
end if
return "[" & theTitle & "](trello" & theURL & ")"