Error: Value cannot be null. Parameter name: source

[bittorrentnz]

Getting an error for https://www.linkedin.com/learning/six-sigma-black-belt

"Value cannot be null. Parameter name: source"

I suspect the issue is a filename with a forward slash (What you should know/road map).

[beardy123]

I have had the same issue and found the main site to be down. A restart won't fix this.
Once I got back on the site the downloader started working again.