Bone heat weighting failed to find solution for one or more bone

I have already tried all advices all this week but still having problems with this issue. Please help!

Your mesh won’t workt. It needs to improve. For example, your topology has tons of double vertices in it. You have a pole under the arm with 11 connections. You have intersecting parts in the nose, ears and crotch. Try simplifying your mesh and using subsurf to give you more subdivisions. You scaled your armature in object mode, rigify doesn’t like that, scale your mesh and apply transforms. If you want to automatically weight this, I would redo the mesh. If you want to use it, then you will have to manually weight paint it and rigify might be too complex for you now. You might try using envelope weights but I’m sue you need to adjust it. Not that you can’t do it, but it will require some study. Look inside your mesh. Here is just a couple of issues.

Don’t give up, it just takes a little while to get the hang of it.