I am trying to upgrade my Linksys WRT1200ac v.1 from 18 to 19.07.03 using the Web Interface (LuCI) method. I keep getting the error message: "The uploaded image file does not contain a supported format. Make sure that you choose the generic image format for your platform."
I changed the file extension from ".bin" to ".trx" and I still keep getting the same error message.
Any help would be appreciated.