The graphic's byte count does not match its data. An undercount is the dangerous one — the parser keeps consuming and eats the command that follows.
Recompute the ^GF byte counts from the actual bitmap.
^XA^FO50,50^GFA,100,100,10,ABCDEF^FS^XZ
^GF where c mod d ≠ 0, or b ≠ c for an ASCII download, or the hex payload length does not match c.
Neither ^PW nor ^LL is set. Both fall back to a value stored in the individual printer, not to a value in the spec — so the same ZPL prints differently on two printers of the same model.
Set ^PW and ^LL explicitly in every format.
The graphic's byte count does not match its data. An undercount is the dangerous one — the parser keeps consuming and eats the command that follows.
Recompute the ^GF byte counts from the actual bitmap.