Glad I could help out. 
Another user warned me about this problem with the package manager in Dynamo 2.0.
So I made some investigations on differents computers with exactly same packages installed, same Revit build and same Dynamo build.
I found one computer where the error occurs when 2 essential packages are already installed.
If I remove these packages, there is no more crash.
Note that installing the package in Dynamo 2.0 crashes Revit but the package is still installed.
On other computers there is no problem when installing the Genius Loci package, so it’s therefore very difficult to solve the issue.
To avoid crashing Revit, a workaround is to download the package from the website https://dynamopackages.com/ and place the contents of the .zip in the folder : C:\Users\%USERNAME%\AppData\Roaming\Dynamo\Dynamo Revit\2.0\packages\Genius Loci
I also experienced crashes when installing other packages with Dynamo 2.0 and so the problem does not seem to be limited to this particular package.
Maybe @jacob.small will have a clue.