Footer Credit not updating any more

I have a custom footer credit in sydney pro. I created it in Customizing - Sydney Pro Options - Footer Credits.
When I try edit the text box, click on the Save and Publish i see this message 04 When I try to deactivate plugins and then try to change text it saved but when i look to front-end the changes are not saved. Where is the problem? website thanks

Hello there,

I checked with the web browser’s console. And it’s displaying the following error.

Probably you would need to resolve HTTPS issue first by reuploading your favicon image.