Hi there @terragirl,
I’m not sure I fully understand what you were referring to here.
There would not generally be a “GET” in the URL itself — an example URL would be something like:
https://example.com/?mailpoet_router&endpoint=view_in_browser&action=view&data=WzMzNiwiYzI4ZWRjOGI2YzA2IiwxNzE2MCwiYzRkN2MzIiw4NTYsMF0
A GET HTTP request would be used to load it in your browser, however there would not be a ‘GET variable after “?mailpoet_router”‘
Everything appears to be working as expected with the newsletter_view_in_browser_url
on my personal test site, and I haven’t seen any other reports of issues related to it. If you can provide some more specific examples of any issue you are running into, that would be helpful. Thank you!