I changed it to:
IIf([Net Principal Balance]=0,"No",IIf([System]="CL",IIf([Import - Daily CL Raw]![Non-Accr-Flag]="Y","NonAccrual",IIf([Import - Daily CL Raw]![Non-Accr-Flag]="N","No")),IIf([System]="MSP",IIf([Import - Daily MSP Raw]![Accrual Status]=2,"NonAccrual",IIf([Import - Daily MSP...