hi! this happend to me fifth time today(apart from last three days) i am having a weird problem of party restricted label on my party name at each and every time someone kicks me off from his/her party or i go solo for a better party, and there it is i cannot invite anyone and i cant go solo on these levels either(too hard sometimes) and i already tried to lock/unlock the party option so that is out of the solution part that never worked.
please help, i think its a bug because the person who kicked me got his party restricted too :P.
Its part of the looping prevention measures. You have to complete the current level in order to get rid restriction.
The basic premise is to prevent a party from breaking up and forming a new party in its wake, then those new parties would proceed through whatever the desired level is, and bypassing the elevator costs they would otherwise had payed to reach that depth.