First of all; you don’t get these errors when browsing the site yourself?
Assuming “no”; Although I have not been able to reproduce the error and it does not seem to be a general one (as with a lot of issues this is specific to the javascript/ CSS that themes & plugins insert), I’ve seen one other user with a similar problem with errors thrown when GoogleBot visited his site.
The solution in that thread would be applicable to your problem as well (except you might have to change the useragent name to the one used by Google Pagespeed Insights).
Hope this helps,
frank
Thread Starter
ditad
(@ditad)
Thanks, Frank. Browsing the site itself gives no errors.
Testing leads to the conclusion that the problem is in the combination of Autoptimize and the W3 Total Cache Minify section. PageSpeed Insights can do its job when I uncheck the HTML minify settings in W3 Total Cache. The other option is to use Total Cache minify, but then I need to uncheck both HTML and JS options in Autoptimize. I am not sure yet which combination gives the best results.
The CSS sections can be combined without errors.
The solution in that thread does not work for my site.
Thread Starter
ditad
(@ditad)
Now I get a warning: Recently an error occurred while creating the CSS / JS minify cache: No sources to serve.
W3 Total Cache warning has discovered the same issue.
ah, but one should never combine different HTML/CSS/JS minification plugins. if you want to use AO, you should disable HTML/CSS/JS minification in W3TC. I should add that to the FAQ really.
frank
Thread Starter
ditad
(@ditad)
Thanks, Frank! Now I just have to find which plugin gives the best results.
just to be clear, you can use W3TC (on the contrary, you really should use a page caching plugin), you just can’t use W3TC’s minification together with AO’s.
frank
Thread Starter
ditad
(@ditad)
Thanks, I understand. Both plugins give same results for minification. I have to find another way to further speed up my site.
you could consider inlining your CSS (if not too large) and/ or inlining background images as data uri’s in your CSS?
what do tests such as google pagespeed insights and webpagetest.org say?
frank
Thread Starter
ditad
(@ditad)
Google is fickle. Yesterday the first thing to do was improving server response time and reordering css and js (not done yet), today I need to resize images (what I already did).
