Power BI cannot unload R scripts

The last versions of Power BI Desktop cannot load R scripts. I've tried with different R Scripts that run perfect in RStudio, for example this script:

x <- rnorm(100)

y <- rnorm(100)

df1 <- data.frame(x,y)

But in Power BI always appears the same two errors:

Details: "EvaluateNativeQueryUnpermitted failure: the query 'x <- rnorm(100) y <- rnorm(100) df1 <- data.frame(x,y)' isn't approved for execution."

Details: "An error happened while reading data from the provider: 'Object reference not set to an instance of an object.'"

What could be the cause of these errors? There is something wrong in the configuration of R in Power BI or there is a bug or error in the Power BI updates?

Thank you so much!