I am not very familar with Confluence, but if altassian programming style holds true, look for a file named
*404*.*. It might be a jsp file or a vm file. You might be able to tell by looking at the url when a page not found error occurs. There might also be a file with the word "*error* in its base file name. Try adding your text and link to either file. I would suspect it should be the 404 file though. You might need to restart Confluence and flush your browser cache.
Please be aware whenever Confluence is upgraded, these changes will need to be reapplied.
If you want to modify existing text, you might be able to do it through updating your language pack.
Two vulnerabilities have been published for Confluence Server and Data Center recently: March 20, 2019 CVE-2019-3395 / CVE-2019-3396 April 17, 2019 CVE-2019-3398 The goal of this article is...
Connect with like-minded Atlassian users at free events near you!Find a group
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no AUG chapters near you at the moment.Start an AUG
You're one step closer to meeting fellow Atlassian users at your local meet up. Learn more about AUGs