In "Site Actions" > "Title, Description and Icon" someone has changed the Web Site Address.
We are trying to changing t back, but receiving an error message "The url 'old url here' is invalid. It may refer to a nonexistent file or folder, or refer to a valid file or folder that is not in the current web.
I have worked out this is due to the length. Anything I enter into Web Site Address with more than 23 characters produces the error. The original url was 26 characters, but I cannot put it back to what it was. The only helpful info I can ind in the logs is an entry stating: "String or binary data would be truncated"
This site was originally SharePoint 2010, and may have had the url altered before the upgrade.
I also have a Development Environment which is the same set up - And that does let me save more than 23 characters