I don’t think that you are able to mess up the forum - and it’s not mine, all I have are a mod’s rights.
@Bill:
Obviously he has older bolts, these are domed at the underside - same as on the caliper.
In this special case, the washer has to be mounted between frame and the 2nd conical washer.
@Damian:
It seems you mounted the upper conical washer (below the bolt’s head) vice-versa.