Cannot access Confluence pages that start with the word "Ambari"

[mpetronic]

Talk about weird... For some reason, something happened in our on-prem Confluence install whereby, when I try to access any page that starts with the word "Ambari" in the title, it get the following error page.

<Error>
    <Code>NoSuchKey</Code>
    <Message>The specified key does not exist.</Message>
    <Key>confluence/display/QUAS/Ambari Installation</Key>
    <RequestId>04EE77B834420E8B</RequestId>
    <HostId>+PJzxK8uPG/HPOf+MlUSmi6cHH3yh34N/s7jz0T5yx0DHwgDcNCcxxa7pzOFRJOnemCwuNhpWJ0=</HostId>
</Error>

Normally, you get a nicely formatted "Page not found" HTML page. Not in this case. When I try to create a new page that starts with "Ambari" I get the same error.

So, we were in this state where the "fortunately" 2 pages we had that started with "Ambari" could not longer be accessed and they had some pretty important installation details we needed.

My college was able to forage around in the Postgres database and found out that he could restore access to the pages using this procedure. For example, assume the original page was titled "Ambari Installation". Then doing the following could be used to recover the page:

1. Change the page title to "xAmbari Installation" in the DB table named "content" . Basically, just make the title NOT start with "Ambari"
2. Open the page in the browser by adjusting the URL to use "xAmbari Installation"
3. Edit the page in the normal UI manner and change the title to NOT start with "Ambari". For example, change the title to "Installing Ambari"
4. Save the page and all is back to normal

Note that, at step #2, in the page tree in the browser and on the actually page, the title was still showing "Ambari Installation" at this stage. But, when you go into edit mode, the title reflected the "xAmbari Installation" name updated in the database.

However, we are still in this state where we CANNOT create any pages that start with "Ambari". I am looking for some clues from the Atlassian gurus as to how we could have possibly gotten into this state.

Is there some logging we could enable and recreate the problem that might help figure out how to remove this limitation?

[Nic Brough -Adaptavist- · Accepted solution]

Five questions spring to mind, although they're more about more information than an actual cause or fix

• Are you behind a proxy?
• Is this all in one space, or can you not use Ambari to start a title in any space?
• Does the word Ambari have any unusual letters in it?  We've both typed it in simple A-Z, but are there letters that look similar but are not A-Z 
• Can you create/use pages with variants - do Amba or Ambarilong break it?
• What does the log say at the point you get the xml error you posted?

[mpetronic]

Nic, you are right on target. After I published this, the next day it dawned on me that we had an Nginx location regex rule that was intercepting "ambari-like" URLs. We had not even thought about the proxy being that cause. It was a simple fix and very glad it was that because who could explain such a bizarre behavior and pin it on Confluence? :) Feel a bit dumb but, oh well, we live a complex world!

Upvoting you just for being on the right track and, you would have led us to Nginx with your first bullet - which was the answer. Thanks for taking the time to chime in.