Getting syntax error in content-single.php

Hi,
Everything was working great on my site and then suddenly my posts were not appearing. I tried turning off plugins etc but it didn’t work. When I turned on debugging I got an error saying
Syntax error unexpected end of file in content-single.php line 1.
I had a look over the code but can’t see anything obvious but php is not my strength. I downloaded the theme again and replaced the content-single file via FTP without changing anything. However I got the same error again. I can’t find the bug. Any help would be great. Thanks.