yearly <- ts(store_578[,6], frequency=365)
fit_yearly <- tbats(yearly)
seasonal <- !is.null(fit_yearly$seasonal)
weekly <- ts(store_578[,6], frequency=7)
fit_weekly <- tbats(weekly)
seasonal <- !is.null(fit_weekly$seasonal)

store_578_ts <- msts(store_578[,-1], seasonal.periods=c(7,365))
autoplot(store_578_ts[,5])

dummy<-cbind(Day1=store_578_ts[,"day1"],Day2=store_578_ts[,"day2"],Day3=store_578_ts[,"day3"],Day4=store_578_ts[,"day4"]
         ,Day5=store_578_ts[,"day5"],Day6=store_578_ts[,"day6"],promo=store_578_ts[,"Promo"])
xreg <- cbind(fourier(store_578_ts[,"Sales"], K = c(1,3)),dummy)
fit_578 <- auto.arima(store_578_ts[,"Sales"], xreg = dummy, lambda=0,seasonal = FALSE, stationary = TRUE)


Error in auto.arima(store_578_ts[, "Sales"], xreg = xreg, seasonal = FALSE,
:   No suitable ARIMA model found