I've had some annoying problems with this issue lately.
while trying to access the blog (message won't disappear),
try this solution explained here:
https://www.raymond.cc/blog/bypass-blogger-content-warning-on-offensive-blogspot-sites
You need to install either Greasemonkey (Firefox), Tampermonkey (Chrome) or Violentmonkey (Opera) depending which browser you use.
Then head over to this GitHub page and click on the Raw icon where it will ask
for your confirmation on the installation of the Blogger Content Warning Skip user script.
Direct download link for github script
Works for me and hopefully for you as well!