My Power BI Custom Visual won't work

I am not finished with finding the source of my problems.

It works in R studio and I have checked that both power bi and R studio run the same version of R. But I found a very interesting link on the web that may be shows the problem. I am checking that out now

https://community.powerbi.com/t5/Desktop/R-Visual-Rcpp-package-error/m-p/488849#M227795

Some below in that page it says:

I had yesterday the same problem. Only reinstalling (or even go back to older versions) did not help.

Only after I deleted the libraries in "<user>/documents/R" and in "<user>/library"  and reinstalled R and installed the packages I needed, the problem was solved.

I think mixed package versions in <user>/library did give the problem for me. I did not know that packages were also in that directory. Only uninstall R en delete "<user>/documents/R" was not enough.

The newest version of PowerBi and R (3.5.1) are now working for me.