My scenario

I was just doing an upgrade of this Umbraco website from 8.4.0 to 8.6.4, everything went smoothly locally, but when it came to doing the upgrade on the live site, I saw a message like this:

The service is unavailable.

The url was as expected

https://codeshare.co.uk/install/?redir=true&url=https%3a%2f%2fcodeshare.co.uk%2f

But for some reason I was getting this weird error and I didn't know how to get past it.

It had to be something to do with the configuration I had on the production site that wasn't on the local one.

I did some googling and I found an issue in the Umbraco GitHub repo which seemed to describe my problem and I found a good solution in the comments.

So for anyone else who is searching for this now or myself searching for it again in 6 months, here was the code which solved it:

The solution

I just needed to add this line to the umbraco location path config setting in the main web.config file.

<httpErrors errorMode="Custom" existingResponse="PassThrough" />

Here it is with the rest of the code that is already in the file:

<location path="umbraco">
    <system.webServer>
        <urlCompression doStaticCompression="false" doDynamicCompression="false" dynamicCompressionBeforeCache="false" />
        <httpErrors errorMode="Custom" existingResponse="PassThrough" />
    </system.webServer>
</location>

The solution was to let the errors pass through. Who knew?

Anyway I hope this helped you out in your hour of need.

Paul Seal

Umbraco MVP and .NET Web Developer from Derby (UK) who specialises in building Content Management System (CMS) websites using MVC with Umbraco as a framework. Paul is passionate about web development and programming as a whole. Apart from when he's with his wife and son, if he's not writing code, he's thinking about it or listening to a podcast about it.

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