I'm getting a 'couldnt save entry' error for a single but all required fields etc are filled I'm getting a couldnt save entry error, but all the fields are filled and there are no additional errors or input highlighting. Has anyone has this problem? Tried clearing the cache and checking the logs but nothing, I was able to fill it in fine before but no longer.

This is a screen shot of the error.



Any help would be appreciated.

Thanks!
Under your single's section settings, you had an invalid URI format for the cy_gb (Welsh) locale: ein heiddo.

URI's can't have spaces in them.  It'd be nice if Craft could warn you that the URI format is invalid (no spaces, all URL safe characters, etc), but it's difficult because Twig code is allowed in those fields and all sorts of characters that aren't URL safe are allowed in Twig markup.