A client I started working for had a lot of gripes with their Umbraco 6 website. Whenever one of the content team tried to create new pages and upload images onto the site, a lot of strange 404s errors would always occur until the site was reset in IIS.
After some investigation, the cause of the issue was that the partner who had setup Umbraco for them wasn't familiar with configuring Umbraco to work in a load balanced environment. The partner had configured it as a normal .NET website. Instead of making the required changes in 'umbracoSettings.config; and the 'web.config' they simply copied the web root onto two servers and left the site to run. This resulted in a lot of Umbraco cache issues and a few database conflicts when content editors had been working on the site at the same time.
If you are reading this wanting to setup Umbraco in a load balanced format, then I suggest you read this tutorial, How To Configure Umbraco To Work In A Load Balanced Environment.
The lack of correct configuration on the live site made a lot of strange things occur in the backend. One of these issues was the 'Oops: this document is published but is not in the cache (internal error)' which was visible against the document link in the 'Properties' tab.
There are several ways you can try to fix this issue, in a web browser add this to the end of your websites URL:
Software Architect, Programmer and Technologist Jon Jones is founder and CEO of London-based tech firm Digital Prompt. He has been working in the field for nearly a decade, specializing in new technologies and technical solution research in the web business. A passionate blogger by heart , speaker & consultant from England.. always on the hunt for the next challenge