I've just upgraded to v3.1.5 from 3.1.4
and it now says...
"The last build succeeded, but the file was deleted later or can't be accessed anymore. Did you move your blog to another server or domain?"
I haven't moved anything anywhere
The debug function says...
"Errors, Warnings, Notices
Fatal error: Only variables can be passed by reference in /content/StartupHostPlus/h/a/haroldstreet.org.uk/web/other/wp-content/plugins/google-sitemap-generator/sitemap-core.php on line 1756"