I have set up a web site using the Customizr theme, including a slider, using the plugin "Regenerate thumbnails", to produce all the image sizes I need. Everything works perfectly on my local computer, but when I deploy to Google App Engine (GAE), the images aren't displayed. I have uploaded them, and I can see them in the wp-admin Media section. They are stored on Google Cloud Storage with URLs like https://storage.googleapis.com/<bucket-name>/<image-name>.jpg, and I can access them over http on those URLs. However, on my deployed WP site, no images show up at all. Also, running the "Regenerate thumbnails" plugin does not produce any new image sizes in the storage "bucket"... I guess the plugin is not compatible with GAE at all, but how should one go about to solve this problem?
In the developer console of my browser, I get a load of error messages like these:
The page at 'https://wp-dot-xxx-yyy-123.appspot.com/' was loaded over HTTPS, but displayed insecure content from 'http://lh4.ggpht.com/7SVmfoMBnl1kQ1su2cWZZTYQbO9KDzeuWql2TPvbnEdAS8T3N9OmUz1fv86Fws9OhoTc_7MEWjpa8MNubBHOxIJrWk4m4_NH=s99999-c': this content should also be loaded over HTTPS.
Failed to load resource: the server responded with a status of 404 (Not Found) http://lh3.ggpht.com/dQWB2UTfQKJMkQIqFBG1TL3PbgYq4GKvf88HjZdbrQQXObIGtz4rTmVkD_vfEk6EXXIm0yOGmzy2UtQv5kw3YCU4f0g-98WUrQ=s99999-c