I've created a hidden survey, and also enabled tokens.
When I send out an invitation url, everything seems fine and the survey displays.
when I modify the token in the url, I get the message 'Toegangscode komt niet overeen' ( Access code does not match), but I still get the link to start the survey?
Did I make an error somewhere in the setup? The link to start the survey should ofcourse not be shown when the access code does not match.
I tried to reproduce the situation with Version 2.06+ Build 150612 and got error message "This is a controlled survey. You need a valid token to participate." which is different from yours.
#Which LS version your are using?
#Do you have any additional setup to show error (Access code does not match)?