Recently, when working with WordPress, I noticed that when using the Master Slider plugin, a content slider/carousel plugin, Firefox was complaining about mixed content from the images. I was using ssl on the site.
Initially I thought this was the wrongdoing of the plugin, but looking through the support pages for the plugin did not yield any immediate answers. The source did not yield any obvious error.
While trying to figure out the problem with the slider, I also notice the warning of the mixed content from the media library of WordPress.
This lead me to think that it may not be the plugin’s fault, and there might be something wrong with WordPress or with the configuration at least.
Looking further into the situation lead me to figure out that I have forgotten to change the url settings in WordPress.
To solve my problem I navigated to
Settings > General
values to use https for the domain to solve the problem.