With the latest BOINC Client (Version 7.14.3) I've just started seeing these messages from my Mac when connecting to CPDN....

Wed Mar 4 12:48:44 2020 | climateprediction.net | Sending scheduler request: Requested by user.
Wed Mar 4 12:48:44 2020 | climateprediction.net | Requesting new tasks for CPU
Wed Mar 4 12:48:47 2020 | climateprediction.net | Scheduler request completed: got 0 new tasks
Wed Mar 4 12:48:47 2020 | climateprediction.net | Message from server: This project doesn't support computers of type x86_64-apple-darwin


Was there a general announcement on this? I thought that this was task/project dependent.....

Well, from the Applications page, supposedly two applications still support Mac OS X Intel. Hadcm3n (no batch released in the last several years) and hadcm3s (last batch issued in mid-Oct last year).

If the OS is Catalina, then there's no 32 bit support now.
And since the apps here are 32 bit, the server would be quite correct.

If the OS is Catalina, then there's no 32 bit support now.
And since the apps here are 32 bit, the server would be quite correct.

Looks like that must be the issue. Darwin 19.4 is the latest version of Catalina.

OK, Thanks.
Then it's safe to say that Mac's running the most current supported version of MacOS (Catalina) can no longer process CPDN files.
Assume there is no plan to enable 64-bit CPDN apps.

...Assume there is no plan to enable 64-bit CPDN apps.

I don't think "plan" is the right word because so many different researchers use CPDN now. I think "intention" might be adequate, but it is still not accurate. The researchers will use what works best for them. Until the majority of CPDN clients are running a pure 64bit OS or until the precision of the 32bit models becomes insufficient for the science things may not change much. I am sure most of the research groups intend to switch to 64bit models at some point. I would guess that every group that does so intend has a different plan for when and how to go about it.

If the OS is Catalina, then there's no 32 bit support now.
And since the apps here are 32 bit, the server would be quite correct.

While at the moment none have been forthcoming even for Linux, in theory at least, the openifs platform does support Macs so that may be a possibility at some point in the future.