JavaScript console.log causes error: “Synchronous XMLHttpRequest on the main thread is deprecated…”

Question

I have been adding logs to the console to check the status of different variables without using the Firefox debugger.

However, in many places in which I add a

Answer 1

I got this exception when I set url in query like "example.com/files/text.txt". Ive changed url to "http://example.com/files/text.txt" and this exception dissapeared.