After installing the Alloy tech demo site, I've run into this error a few times on my first install when trying to log into the editor.
Here are a few tips to try and solve it:
1. Make sure you are using the right user-name and password. I have found that when I'm using my Windows account and there are no EPiServer users added, typing in a wrong username and password combo will cause this issue.
2. Switch to only using Windows Authentication. To fix the issue open your web.config in the [Configuration] ->EPiServer -> Web.Config and go to the 'roleManager' section. Change the role and membership provider to use the Windows versions, as below:
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