Same thing with OP, but it happens in more than just level 50 roulette. Had it happen in Trials and Expert roulette. With Expert, I was in a party.

ISP:
TPG

Type of Internet Connection:
DSL

Internet Connection Speed:
500Kbit/s

Date & Time:
Since emergancy maint.

13th November 2015 17:19 GMT + 11

Frequency:
Always


Character Name:
Paca Kuma

Race:
Miqo'te M

World:
Chocobo

Class/Level:
White Mage level 60

Area and Coordinates:
Anywhere I believe, I was in Idyllshire

Party or Solo:
I've seen it trigger with both party and solo

In-Game Time:
08:00 ET

Steps:

1) Sign up for Duty Roulette. I have seen it happen for Duty Roulette: Trials while I was solo and also for Duty Roulette: Expert when I was with someone else.

2) Wait a few minutes.

3) Duty Status party forming window will show 0 for all roles after a while.

It will show like below.