I think for me it helped to turn my WIFI on and off again.
"Errno 98" basically means that a network port is already in use and by disabling your internet, you can close all the ports (I think?)
@manny
PDFs are currently not supported by the reader.
You can see the supported file formats when you click on this button.
a5b3e81e-53bf-4660-95c2-117e29e691ba-image.png
What you could try for now is to convert the pdf to html or so. https://convertio.co/ja/pdf-html/
@manny
For now the extension is optimized for google chrome. Export to other browsers will come tho. Although I think there are some people using it with brave in discord. I dont so I cant help you with that, but maybe you can ask there and some of the people that do use it with brave can help you.