I am afraid that the button command is working the way it suppose to. “Resume” command by definition, will go to the place last call was made from. So, if there is no last “Call” (no title play) than command will generate an error. You can give that button “Link Tail PGC” command and from there you can direct it as you desire, with IF, THAN, OR instructions, using your R(4) = 1 Title condition.
I had no problem with your download.