Hi Limmyfiz, you can give me more details about the problem by opening an issue on Github at https://github.com/jscher2000/Save-webP-as-extension/issues/ or sending me an email to jscher2000@outlook.com.

(Update: version 1.5.1 pops up a little panel with some more options when the script is denied permission to read the page. Previously that just caused silent failure.)