Mmm, something strange is happening. Probably linked to your theme. Could you try to use one of the WordPress default themes as a simple test?
Then we could try to modify the code a bit. Below this line:
$html = str_get_html( $buffer );
Add:
if ( empty( $html ) ) return $buffer;
Let’s see what happens.
It works with default theme. I’m only getting a blank page when I set the plugin options to picturefill? Tried adding that to 119 but still the same thing.
All plugins are disabled, default theme, and this happens? This sounds impossible… Of course the plugin has been tested on many kind of installs and thousands of users are using it. There is something unique about your install, we should find it.
Did you try on your real website, online? (not local)
Alternatively, you can use the retina.js method, that wouldn’t go through the HTML rewriting.
Sorry worded that wrong… Works fine with default, but doesnt work with my theme even with all plugins disabled. I’ll try on my staging and see if it works. If not I’ll try out retina
Mmm. It seems your theme is doing something it is not supposed to do. Plugins are made optional but Themes are a base. Whatever special feature this theme has, it should be optional or be in a plugin. Which theme is it?