An unexpected error occurred in Octopus v2018.6.9: this.replaceLoop is not a function

I keep seeing this message at the top of the screen after saving changes to a deployment process.

Full text is:
An unexpected error occurred in Octopus v2018.6.9: this.replaceLoop is not a function

TypeError: this.replaceLoop is not a function
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Hi Darryl,

Thanks for getting in touch! I’m terribly sorry you’re hitting this unexpected and very annoying issue we’ve introduced. We reproduced it in 2018.6.9 and the fix for it was included in the next patch release (2018.6.10) and you can refer to the issue here.

Would you be able/willing to upgrade to at least that version (preferably the latest) and let me know if that fixes this behavior for you?

Let me know how you go or if you have any further questions moving forward. :slight_smile:

Best regards,


Hi Kenny,

Thanks for the quick response. It’s a cloud instance. How do I upgrade it?

Hi Darryl,

Andrew from the Octopus Cloud team here. Yes I can certainly upgrade you to the latest Octopus version (we do run upgrades in the background, but they take some time to roll out across the fleet). I can see that you’re currently outside your maintenance window when upgrades will occur, so I can do one of the following:

  1. If it’s OK with you, I can kick off an upgrade right now (or anytime), but you may experience a short outage while Octopus is updated; or
  2. I can trigger it to occur during your next maintenance window (which should occur in about 18 hours)

If I don’t hear from you, I’ll set a reminder to get the upgrade kicked-off tomorrow during your window, and hopefully your problems will be resolved.


It’s fine to do it any time. I’m still setting up the deploy process.

Hey Darryl,

Sorry to keep you waiting, I didn’t catch your reply! This is all done for you, I triggered the upgrade on Saturday morning (my time) during your outage window as planned, so you should now be running 2018.6.14, and hopefully the issue is resolved.

If you do still find issues, post in here and I’ll dig in a little deeper :slight_smile:.


I haven’t seen the error since. Thanks.

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