Authentication failed for admin 400 error

I've tried uninstalling 11.0SP14 and did a new installation of 12.0SP9. Again, no issue during the installation process but still getting the same error message though. I'm thinking it is a database issue, but I can't figure out what I'm missing. 

I've tried uninstalling 11.0SP14 and did a new installation of 12.0SP9. Again, no issue during the installation process but still getting the same error message though. I'm thinking it is a database issue, but I can't figure out what I'm missing. 

Error 400 is pretty generic. Have you set up IIS correctly? --> https://www.youtube.com/watch?v=rlgyGM8yTTI ? 

Did you setup the database during installation or did you reuse an existing one?

Yes I set up my IIS correctly. As for the database, I am reusing. I did figured out my issue, though. Had to set fipsMode="true" in my connection string, but didn't realized it was case sensitive. Capitalizing the "M" solved the error