If you see the error proxy-url-file-3A-2F-2F-2F , it usually means an application tried to save the URL but double-encoded the special characters: %3A is the colon ( : ) %2F is the forward slash ( / )

file or a manual proxy setting where a local or network file path is being used as the configuration source. 1. What is a Proxy Auto-Configuration (PAC) File?

To understand what this "feature" represents, you have to decode the syntax:

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