Mac Driver Correction for Catalina 10.15.5 and greater

Modified on Thu, 22 Jun 2023 at 09:47 AM

In the Spring of 2020 Mac began introducing security changes that affected the RT Systems programmers and how the drivers are loaded. In the OS release 10.15.5, Mac included the IDs for the RT Systems cables in the operating system drivers. This will be a great improvement going forward.

Unfortunately for all of you who we helped install and allow the RT Systems drivers in the past and have now upgraded to Catalina 10.15.5 or greater, you now have a conflict. Not hard to fix and we will be glad to help again if you need us.

The fix involves getting the RT Systems drivers out of the way and letting the system drivers take over. The steps for that correction are:

Note: The RT Systems cable should be connected to the computer but NOT to the radio for this process.

  • From the Finder menu at the top of your screen (this is all Mac not the RT programmer), select GO => Computer => Macintosh HD => Library => Extensions.

  • In the Extensions directory, find rtsystemsusbserialdriver.kext. Identify that file and move it to the trash. It will disappear from this directory listing completely. If it does not, this step was not completed tproperly.

  • Reboot the computer: Select the Apple symbol at the upper left of the screen and then select Restart from the menu that opens.

  • Once the computer completes the reboot, open Terminal. We do this by clicking on the search symbol (the magnifying glass) at the upper right. When the Search opens, type Terminal and press enter.

  • At the Terminal prompt type sudo kextcache -i / (Note: There is a space before the "-" and one after the "i" and the forward slash "/ " (that's the one under the question mark on the keyboard) is a critical part of the command.. it won't work otherwise). Press Enter.

  • When prompted for your password, enter it. You will NOT see it enter. Be careful to enter it correctly since you can't see it. Press enter when you finish entering it.

  • This is the part of the process that is a little tricky. You want to be sure to give the machine plenty of time to work on its own without any interference from you. It will appear that nothing is happening with the cursor blinking at the left of the screen. Then you may get several messages about access denied or permissions and lots of other things. These are not important. What is important is that you leave the machine alone to work (30 seconds to 5 minutes, maybe).

  • You will know the machine is finished when the full prompt appears again with the cursor at the end of it (Look back up where you typed the command. The prompt will be the same as the one on that line.)

  • Reboot the computer... yes, for real. I wouldn't say it if it were not so!! It takes this second reboot to establish the connection between the cable and the system drivers.

  • When the computer comes up again, run the programmer and try Communications | Get or Send data (whichever you were trying before all tis started). You should have success now and in the future.


If you have any problems working through this process or you are just not comfortable with the commands as described, we are here to help. Monday through Friday 10 - 6 Eastern time and Saturday 11 - 3 Eastern time. Support: 404-806-9561

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