Denis Ryabov

@wer0ckz Multisite is not supported yet.

FOUC is a result of issues with above-the-fold css generation (usually it happens if one of stylesheets has a parsing error). We are working on some improvements, but it’s hard to say when the process will be done.

As a temporary solution it’s possible to disable above-the-fold css (there is a switch in “Advanced” settings > “Eliminate render-blocking JavaScript and CSS in above-the-fold content” section > “Above-the-fold CSS”), but most likely in this case PageSpeed Insight result will be limited by 90 points.

Yes, just disable “Load external files” to fix it in now. In the next release this feature will be fixed, but it may take few days to be released, because of there are some other minor fixes we are going to test and include into release.

Most likely the problem is in “Leverage browser caching”/”Load external files” setting. We have found it doesn’t rebase CSS files correctly. It will be fixed in the next release.

Could you disable PageSpeed Ninja plugin? We will check content of original css files to found how it is possible to get “double-domain” URLs in generated minified styles.

“Caching” in “Reduce server response time” section.

Do you have “” enabled in the Advanced settings tab? If yes, try to disable it and check again, probably the issue is related to cache conflict if website may be accessible via both http and https protocols.

The notice about undefined variable ver is not related to the PageSpeed Ninja plugin. It just means that there should be a line $ver = ‘some value’; somewhere inside of functions.php (maybe it is commented out, it is hard to say having a piece of the file only).

The mentioned warning about readdir() means that directory wp-contents/plugins/psn-pagespeed-ninja/admin/sessions doesn’t exist (or the plugin has no permissions to read its content). It is quite strange, because of that directory is created automatically when the plugin is installed, and there is no code to remove it in some a way. Could you check that directory exists and readable?

As to the disk space, PageSpeed Ninja creates files in the following directories (relative to the website root):

/s – merged js and css files, loaded external resources
/wp-content/plugins/psn-pagespeed-ninja/cache – cached pages for unauthorized users
/wp-content/plugins/psn-pagespeed-ninja/ress/cache – internal cache of optimized fragments of html

Also there are optimized and rescaled images aside with original files. Note that PageSpeed Ninja keeps records about created files and removes all of them at uninstallation.

PageSpeed Ninja is still in the beta stage, and so some errors are possible and we are interested in catching and fixing them as soon as possible. That’s why we implemented a way to store all PHP warnings and errors in error_log.php file, because 1) many users have troubles with finding error_log file on the server, and 2) usually error_log collects error messages only, but in many cases warnings do matter too. The text “Size of …/error_log.php file is 25.4” means that size of that file is 25.4Mb, and it is recommended to either disable this kind of logging (to don’t get huge file), or to send us that file for further analysis. You can disable this logging in the Advanced tab of PageSpeed Ninja settings page.

New webfonts loader is our aim for the next release (or one of the next releases).

We will try to fix it in the next release. As a test, could you try to edit wp-content/plugins/psn-pagespeed-ninja/includes/class-pagespeedninja.php and replace signs in “1000” number (close to the of the files), so that the code look like:

        // start buffering
        add_action('template_redirect', array($plugin_public, 'template_redirect'), -1000);
        // end buffering
        add_action('shutdown', array($plugin_public, 'shutdown'), 1000);

Most likely it should fix conflict with All in One SEO Pack.

As to the ETag header in the wp-content directory, this issue will be fixed in 0.9.14. But in the “s” directory, it is the feature, because of any changes in source files result in new file name in the “s” directory (see e.g. 31b136.css and 6a175d.js in your examples), and cache validation is not necessary that allow us to save several useless requests to the server.

We didn’t tested it with IIS, but the plugin is written keeping in mind that it should be able to run on Windows OS. And we did some tests with Apache on Windows, where the plugin worked perfectly. So, most likely the plugin should work on IIS as well, but if you found some issues there, just inform us, and they will be fixed in short time.

@dosolnce Could you send us ([email protected]) a screenshot and complete webpage sources (Ctrl+S in your browser)? If there are error messages in browser’s webdeveloper’s console, include them into email too, please.