403 error when trying to add a new slide to the Slideshow Gallery
I am trying to add a new slide to the slideshow gallery. I complete all the fields on the Save a Slide screen and select a file from the Media Library. When I click on Save Slide, I get an error - 403 Forbidden - Access to this resource on the server is denied.
The URL in the address bar at the time of the 403 Forbidden error is
When I look at the developer tools console, I see this error - The character encoding of the HTML document was not declared. The document will render with garbled text in some browser configurations if the document contains characters from outside the US-ASCII range. The character encoding of the page must be declared in the document or in the transfer protocol.
I'm using Wordpress multisite.
Can you please help.