https://www.askwoody.com/forums/topic/unable-to-subscribe-to-any-askwoody-thread/

Subscribe to new topics button after the install of bbpress 2.6.19 is not working.
This may be a skin issue interaction with Dev4press’s bbpress theme?

[@sbask Participant 2 weeks, 2 days ago]

Anything? I can’t update to 2.6.19 until this is resolved.

[@johnjamesjacoby Keymaster 2 weeks, 1 day ago]

Hi there. I’m looking into this now.

[@johnjamesjacoby Keymaster 2 weeks, 1 day ago]

Hi @sbask,

I confirmed that this is a regression in bbPress 2.6.19. That release changed the nonce generated for subscription links. The bundled bbPress theme package accepts both formats, but third-party theme packages such as GD Quantum Theme can reject the new format.

I restored compatibility in trunk and the 2.6 maintenance branch, with regression coverage for both formats. The fix is scheduled for bbPress 2.6.20:

https://bbpress.trac.wordpress.org/ticket/3711

Please accept our sincere apologies for the mix-up, and for the extra work and delay this caused you. Thank you for reporting it and for following up.

[@sbask Participant 17 hours, 58 minutes ago]

Fixed. Thanks.