I noticed some people are still going through this problem:
-- Fixes --
1. il2cppdumper files, metadata, and .so file are all in same folder
2. Use il2cppdumper latest version
Latest version here
3. Correct unity version
How to get unity version
4. Try different mode
5. Game has...
I found that i had recieved the Adblocker error message because Firefox has by default in the options to disable tracking protection, i disabled for this site and is now resolved!