Starting on January 6, 2020, the firmware versions older than 0.6.0 will be retired from the cloud compiler. Trying to compile with the Web IDE or CLI against a retired version will give this message.
Error: Compiling for this version of Device OS is not supported anymore. Upgrade your device and try again.
The most likely reason you’ll run into this situation is that some time in the past you changed the version of Device OS you target when compiling for a particular device in the Web IDE and didn’t go back to select a more recent version. Open the Devices tab and select the default release in the Device OS target dropdown. Then compile your application again and when it gets flashed, your device will be upgraded to a newer version of Device OS.
Targeting a retired Device OS version:
Switch to targeting a supported Device OS version:
For more information about updating Device OS, see the Particle documentation.
Note that devices running old Device OS versions will still be able to connect to the cloud. Only the ability to cloud compile against those version is being retired.