After upgrading to the macOS High Sierra 10.13.4 system, a warning appears after running a 32-bit application to remind users that future versions of macOS may not support 32-bit applications. Apple informed developers last summer that High Sierra was the last system to support 32-bit applications and all Mac application upgrades and existing applications must support 64-bit after June 2018.
In order to facilitate developers to test 64-bit application compatibility macOS 10.13.4 also provides a new 64-bit test mode, developers can use the terminal command to open:
sudo nvram boot-args=”-no32exec”
After executing this command, you need to restart the Mac. The 32-bit process failed to start in 64-bit test mode. When the computer is in 64-bit mode, opening a 32-bit application or relying on a 32-bit 64-bit application, a reminder pops up: The application can not be opened. To disable this mode, enter the following command and restart:
sudo nvram boot-args=“”
Apple said in a future release, the 64-bit test mode can provide more information to help developers test the software. Finally, Apple also suggested that developers, if you do not use the Mac App Store distribution applications, should upgrade their applications to 64-bit, otherwise the future macOS system will not be able to continue to support 32-bit applications.
Reference: idownloadblog
