Tumblr: Resolve Non-HTTPS URL Error
An easy trick to resolve the non-https error that Tumblr users are facing recently.
Error message: “uh oh we couldn't save your theme. looks like your custom theme references from non-https URLs. please try again using only https URLs”
Before the problem: Edit appearance > Website theme > edit theme > edit HTML
During the problem (while editing HTML): Ctrl + F (Cmd + F) > search for "https", replace with "http" > then, search for "http", replace with "https"
Update Preview > Save






