Error If

Hi everyone,
i have a problem with this If

Range("C1").Select
ActiveCell.FormulaR1C1 = _
"=IF(RC[-1]=""lun"",CONCATENATE(RC[-2],"" TO "",TEXT(DATE(YEAR(RC[-2]),MONTH(RC[-2]),DAY(RC[-2]+6)),""AAAA-MM-GG"")),IF(RC[-1]=""MAR"",CONCATENATE(TEXT(DATE(YEAR(RC[-2]),MONTH(RC[-2]),DAY(RC[-2]-1)),""AAAA-MM-GG""),"" TO "",TEXT(DATE(YEAR(RC[-2]),MONTH(RC[-2]),DAY(RC[-2]+5)),""AAAA-MM-GG"")),IF(RC[-1]=""MER"",CONCATENATE(TEXT(DATE(YEAR(RC[-2]),MONTH(RC[-2]),DAY(RC[-2]-2)), _
""AAAA-MM-GG""),"" TO "",TEXT(DATE(YEAR(RC[-2]),MONTH(RC[-2]),DAY(RC[-2]+4)),""AAAA-MM-GG"")),IF(RC[-1]=""GIO"",CONCATENATE(TEXT(DATE(YEAR(RC[-2]),MONTH(RC[-2]),DAY(RC[-2]-3)),""AAAA-MM-GG""),"" TO "",TEXT(DATE(YEAR(RC[-2]),MONTH(RC[-2]),DAY(RC[-2]+3)),""AAAA-MM-GG"")),IF(RC[-1]=""VEN"",CONCATENATE(TEXT(DATE(YEAR(RC[-2]),MONTH(RC[-2]),DAY(RC[-2]-4)),""AAAA-MM-GG""),"" TO "" _
,TEXT(DATE(YEAR(RC[-2]),MONTH(RC[-2]),DAY(RC[-2]+2)),""AAAA-MM-GG"")),IF(RC[-1]=""SAB"",CONCATENATE(TEXT(DATE(YEAR(RC[-2]),MONTH(RC[-2]),DAY(RC[-2]-5)),""AAAA-MM-GG""),"" TO "",TEXT(DATE(YEAR(RC[-2]),MONTH(RC[-2]),DAY(RC[-2]+1)),""AAAA-MM-GG"")),IF(RC[-1]=""DOM"",CONCATENATE(TEXT(DATE(YEAR(RC[-2]),MONTH(RC[-2]),DAY(RC[-2]-6)),""AAAA-MM-GG""),"" TO "",TEXT(DATE(YEAR(RC[-2] _
,MONTH(RC[-2]),DAY(RC[-2]+0)),""AAAA-MM-GG"")))))))))"
Range("C2").Select


what is the issue?

please help me!

thank you
L

my guess is you tried to a formula much longer than the max of 255 characters

i write it down again:
ActiveCell.FormulaR1C1 = _
"=IF(RC[-1]=""LUN"",CONCATENATE(RC[-2],"" TO "",TEXT(DATE(YEAR(RC[-2]),MONTH(RC[-2]),DAY(RC[-2]+6)),""AAAA-MM-GG""))," _
IF(RC[-1]=""MAR"",CONCATENATE(TEXT(DATE(YEAR(RC[-2]),MONTH(RC[-2]),DAY(RC[-2]-1)),""AAAA-MM-GG""),"" TO "",TEXT(DATE(YEAR(RC[-2]),MONTH(RC[-2]),DAY(RC[-2]+5)),""AAAA-MM-GG"")), _
IF(RC[-1]=""MER"",CONCATENATE(TEXT(DATE(YEAR(RC[-2]),MONTH(RC[-2]),DAY(RC[-2]-2)),""AAAA-MM-GG""),"" TO "",TEXT(DATE(YEAR(RC[-2]),MONTH(RC[-2]),DAY(RC[-2]+4)),""AAAA-MM-GG"")), _
IF(RC[-1]=""GIO"",CONCATENATE(TEXT(DATE(YEAR(RC[-2]),MONTH(RC[-2]),DAY(RC[-2]-3)),""AAAA-MM-GG""),"" TO "",TEXT(DATE(YEAR(RC[-2]),MONTH(RC[-2]),DAY(RC[-2]+3)),""AAAA-MM-GG"")), _
IF(RC[-1]=""VEN"",CONCATENATE(TEXT(DATE(YEAR(RC[-2]),MONTH(RC[-2]),DAY(RC[-2]-4)),""AAAA-MM-GG""),"" TO "",TEXT(DATE(YEAR(RC[-2]),MONTH(RC[-2]),DAY(RC[-2]+2)),""AAAA-MM-GG"")), _
IF(RC[-1]=""SAB"",CONCATENATE(TEXT(DATE(YEAR(RC[-2]),MONTH(RC[-2]),DAY(RC[-2]-5)),""AAAA-MM-GG""),"" TO "",TEXT(DATE(YEAR(RC[-2]),MONTH(RC[-2]),DAY(RC[-2]+1)),""AAAA-MM-GG"")), _
IF(RC[-1]=""DOM"",CONCATENATE(TEXT(DATE(YEAR(RC[-2]),MONTH(RC[-2]),DAY(RC[-2]-6)),""AAAA-MM-GG""),"" TO "",TEXT(DATE(YEAR(RC[-2]),MONTH(RC[-2]),DAY(RC[-2]+0)),""AAAA-MM-GG"")))))))))"

but it doesn't work!