on window "GL Journal Generator" choose "GL Category" = none (record from system client, so have id =0)
run "generate GL journal".
when MJournal is created, it set its GL_Category_ID = 0 so make exception "Fill mandatory fields: : GL Category - GL_Category_ID is mandatory."
solution: not sure, but i think we can filter out record none of system from list of "GL Category"
hi , any reason to keep record "none"?