Added a Formula but wont show up in the results - no errors and the column in completely missing? Any suggestions? the formula is (SUM{custbody_taxamountoverride}+{custbody_taxamountoverride2})/(NULLIF{taxtotal},0)

Are you Grouping results?

You chose Sum, but also added a + symbol. Try taking one out. Could you write out what you'd like to do?

@Tim_Pedersen that worked