jomo imputation_error

Thanks for the complete code. For the future, the preferred format is a reproducible example, called a reprex.

The error messages tell the story: X isn't found because you can't subset a closure (i.e)., function).

cov[, c("sex", "ability", "grip", "bmic")]

will never work. This is why you should never use reserved names like cov. Always check by just entering it

cov

before trying to assign an object to it.

cov<-na.omit(v)

If v had been found, you might have been able to skate by.

The troubles begin, however, with test_impute. How have you satisfied yourself that it actually is in the namespace?