Hi Ammar,
Welcome to the QuEra forum!
In regards to your problem there seem to be two things happening here.
For the warning that’s emitted from using Bloqade we strongly recommend updating to the latest version of Julia 1.8 or higher if you can.
The second error you see from atoms = generate_sites(...) is a bug with the pretty printing which has been fixed very recently in the latest version of Bloqade (0.2.2). We recommend updating Bloqade to this version in your environment as well.