Error 503 Backend fetch failed

Hi,
I’m really struggling with my website. The latest issue I have now is that it won’t load an image that I’ve added into the header on the front page. The error message I get is below, which a quick google tells me is a server issue. I’ve given you access in the Dashboard.

I have had Hummingbird set up, and was trying to get my page loads down using caching, but apparently I’ve messed a bunch of things up with it, so I’ve ended up deactivating it. I don’t know if that’s related?

Error 503 Backend fetch failed
Backend fetch failed
Guru Meditation:
XID: 267180200
Varnish cache server

As a side note, I’ve switched to Thrive quiz plugin, because Forminator wouldn’t present a quiz the way I wanted it (one question on a page, moving through) and I couldn’t make it look pretty. In doing so, I’ve had to disable Defender as well, becuase it doesn’t play nicely with the builder. My plan is to reactivate Defender once I’ve pushed it live, but I thought I’d let you know about the clash.
Also, I’ve again not been able to get a chat working – I just get a loop, fill in the form to start a chat, hit the submit button, the popup goes away and nothing else happens. Not expecting help on all these other things, just letting you know about what else is going on around WPMUDev products for me at the moment.

Thanks for helping!

  • Dimitris Kalliris
    • Support Team Lead

    Hey there OneRedSock

    About the “Error 503 Backend fetch failed” error, this comes from Smush CDN.
    It seems that somehow the CDN URL is broken so I forwarded this to our Smush lead dev to have a better look.

    My plan is to reactivate Defender once I’ve pushed it live, but I thought I’d let you know about the clash.

    I don’t see any previous reports around Thrive products and Defender, so please do enable it back and if you’re still having issues create a separate thread about it as we’re keen on having different threads for each issue.

    About our live chat, can you please let me know about the followings:
    – operation system
    – browser (and its version)
    Have you maybe tried via an incognito browser without any active browser extensions?
    Please advise!

    Thank you,
    Dimitris

  • OneRedSock
    • Flash Drive

    Hi Dimitris,
    I uploaded the image again and linked to that instead. Seemed to fix it. Would be good to know how to avoid it in the future.
    I’ll open another thread about the Defender and Thrive Quiz Builder conflict.
    Thanks
    S

    PS Is this now a thread about Smush? Because there’s a conflict with Thrive Quiz – once I got the quiz built, it won’t load for visitors while I have Smush active.

  • Dimitris Kalliris
    • Support Team Lead

    Hello OneRedSock

    I appreciate the update on this. I can also see that there’s no error in the browser’s console now.
    I’ve forwarded your question to our lead developer, as when he tried to access the staging site it was returning a 503 for him so he couldn’t check it before your fix.

    PS Is this now a thread about Smush? Because there’s a conflict with Thrive Quiz – once I got the quiz built, it won’t load for visitors while I have Smush active.

    We prefer having separate threads per member and per issue, so it’s easier for more staff/devs to follow up when needed.
    Before doing so, as I can see a recently reported issue, can you please try the workaround that our Second Level Support guy shared here?
    https://wpmudev.com/forums/topic/smush-pro-images-are-missing-even-after-disabling-smush-pro/#post-3724965
    If that doesn’t work for you, then please create a new thread or start a live chat with us. :slight_smile:
    https://wpmudev.com/hub/support/#wpmud-chat-pre-survey-modal

    Thank you,
    Dimitris

  • Dimitris Kalliris
    • Support Team Lead

    Hello there

    It seems that this is an issue when pushing between live and staging environments. I also gave this some tries and it seems that it gets resolved if I re-check the API status in Smush settings or if I de/re-activate Smush CDN. Another workaround would be to completely reset Smush settings.

    Please let me know if this issue is happening again on your site and none of the above can help to resolve it.

    Warm regards,
    Dimitris