The crashes are caused by a recent update of Google Drive File Stream on Mac. Please download and install this experimental version which fixes these crashes. A stable update will be released as soon as possible.
On a side note: If there is ever a problem that a native Boxcryptor application crashes / does not work for whatever reason, you can use Boxcryptor Portable to access your encrypted files. Boxcryptor Portable does not require an installation (and also uses a different technology stack as the native clients) - so chances are very high that Boxcryptor Portable works even if the regular installation does not. You can download Boxcryptor Portable here: