Wordpress error: Cannot write style-custom.css file

I upgraded to WordPress 3.8 and looking around I opened

“Apearance --> Customize”

and then hit

“Close”

without making any changes.

Now my website is down and I can’t access wp-admin. When I try either I get;

{“success”:“-1”,“alert”:“Cannot write style-custom.css file, you may try setting the style-custom.css file permission to 755 or 777 to solved this. ( If file does not exists, you have to create it yourself )”}

I found that I have four themes listed in;

/var/www/wp-content/themes

1. bluediamond-v 1_05 (This is the only one that has the “style-custom.css” file
2. twentyfourteen
3. twentythirteen
4. twentytwelve

I changed the existing “style-custom.css” file permissions to 755. I still can’t access wp-admin or the website - I continue to get the same alert.

Any help is very much appreciated