I am sorry but I don't understand the error description.
What exactly are you trying to do when you get the described error message?

I'm also gettin this error.
While I'm trying to send token based e-mail to participants, I got this error.
But there is no problem with mails. Everything seems OK.
I only wonder about what this error is and what it is about.

Edit: I've updated to 10120 and there is no error right now.
Edit 2: I've sent new survey and same error again.

Getting the same error after upgrading to 10120 (from 1.90)

It happened on the first screen when sending out email invitations, one line for each message sent out:
"Warning: array_shift() [function.array-shift]: The argument should be an array in /home4/limesurvey_191/admin/tokens.php on line 1646"

It did not happen in the second batch, and I will check when sending out more invitations later today.

I think I've experienced this warning as well, if I run over it again, I'll take a look. Might be later today even with some token tests.

I'm also experiencing this issue.
$tokenids seems to be NULL; it's supposed to be initialized at

line 31 in tokens.php:
if (!isset($tokenids)) {$tokenids=returnglobal('tids');}

So this suggests 'tids' is NULL. Hope someone can take a look at it soon!

Regards,

Fixed in rev 10178

New 1.91+ version released