Unfortunately Garmin Express for Mac is still not compatible with the Monterra. The PC version is now compatible since v3.2.18 most likely because Windows natively supports Media Transfer Protocol (MTP) mode but the Mac version is still not compatible.
Yes, I'm aware of the Windows GE fix and that was appreciated by many Monterra customers who use the Windows OS - no doubt. I used it to finally update my Lifetime Maps but I dislike using the Windows OS if at all possible. The thing that I find perplexing is that Garmin BaseCamp and Garmin MapInstall can both recognize the Monterra when connected to my Mac. Granted BaseCamp has a few issues but in general they both work fine reading and writing to internal and external storage.
In the old days of software development, we'd say that the "righthand isn't talking to the lefthand".
