Short description:
The guild doesn't receive new Guild Quests. The first symptoms seem to be that you don't receive a waiting Guild Quest (when your current Guild Quest isn't finished in time).
Screenshot:
Since the absence of something isn't easily screenshotted, I use 2 screenshots on 2 subsequent days.
30 August:
31 August:
Possible cause:
Unknown, might be related to players joining/leaving, not finishing your guild quest in time...
Prevention:
Unknown
Workaround:
Unknown
you could try letting players leave and rejoin (beware there is a 24h cooldown before you can rejoin a guild) (Doesn't work tried myself)
Related: