Why does calling dyn.load in a for loop crash my R session?

Question

R (3.3.2, Windows 7) crashes after about 1000 iterations of dyn.load() being used in a for loop. This does not happen in Ubuntu. This behaviour is observed for dll files created from Rcpp and TMB code, but I don't think it is related to either of these packages. The crash message is:

Problem Event Name: APPCRASH
Application Name:   rsession.exe
Application Version:    1.0.136.0
Application Timestamp:  583f5668
Fault Module Name:  testRcppRepeatDynLoad.dll

The following is a mimimal reproducible example on my computer:

First, create an Rcpp package called testRcppRepeatDynLoad (in Rstudio, create package in new directory, select 'create package with Rcpp'.). Building the package with CTRL-SHIFT-B creates a dll file in the src folder, which we will load using dyn.load.

This code crashes the R session after 1050 iterations:

while (i < 2000) {
    i = i + 1
    print(i)
    dyn.load('src/testRcppRepeatDynLoad.dll')
    dyn.unload('src/testRcppRepeatDynLoad.dll')

}

The same thing happens for a dll file created by TMB::compile.