segfault issue

[quantifish]

I am getting a segfault issue when I load both the StanEstimators and the adnuts packages (the sparse_M branch). Initially I thought that this was an RStudio issue, but I have since tested in R from the command-line. I have the R version and the issue in the screenshot below plus my OS specs in the next screenshot. I tested this from a very clean R (I deleted all other packages and then did this test). I note that if I load only one of the packages then everything works OK (e.g., if I load the adnuts package on its own then I can work through things until I need StanEstimators functions. Let me know if you need further details.