The assume macro doesn't like comma separated data statements.
Example:

Code:

struct x   y db 0, 1 ends

Suggested fix in MASM.INC
Original:

Code:

macro def@assumed reg,name,def  { match vars, reg#@assumed \{ reg#@assumed equ reg#@assumed, \} ...

Fix:

Code:

macro def@assumed reg,name,[def]  { common  match vars, reg#@assumed \{ reg#@assumed equ reg#@assumed, \} ...

Today's update in 1.71.03 package fixes this bug.