I keep getting error on this, can someone help me

Question

delta_gamma = 0.05

MRW.data <- MRW.data %>% 
                  mutate(ln.gdp.85 = log(gdp.85),
                         ln.gdp.60 = log(gdp.60),
                         ln.gdp.growth = ln.gdp.85 - ln.gdp.60,
                         ln.inv.gdp = log(Inv.gdp/100),
                         Non.oil = factor(Non.oil),
                         intermediate = factor(intermediate),
                         OECD= factor(OECD),
                         ln.ndg = log(pop.growth /100 + delta_gamma)) %>%
  select(country, ln.gdp.85, ln.gdp.60, ln.inv.gdp, Non.oil, intermediate, OECD, ln.ndg, ln.school, gdp.growth, ln.gdp.growth)
skim(MRW.data)

Show in New Window Error in select(): ! Must subset columns with a valid subscript vector. x Can't convert from to due to loss of precision. Backtrace:

1. ... %>% ...
2. rlang::cnd_signal(x) Error in select(., country, ln.gdp.85, ln.gdp.60, ln.inv.gdp, Non.oil, :

x Can't convert from to due to loss of precision.