I am using Basecamp from V2 to 4 always fine with my Nuevi 2595 for some time now.
I made recently a new installation of OS X 10.10.5 and one of the latest Basecamp 4.x versions (now at 4.5.2). Now suddenly Basecamp does not load any Content from my Nuevi. The device is recognised but any import ends with an empty list, no errors displayed.
Just to compare I installed a very old Basecamp V2 -> no problem to import. Thus the error is not with my OS or hardware.
Thanks, Helge