Hi Benoît,
Apologies for this issue. Unfortunately, it is very difficult for us to test every board. Especially targets that are not officially supported by pyOCD. We are actively working on a new debugger in Studio that should improve the number of supported boards and the general stability of debugging. Until it is ready we recommend:
a) One difference between 1.3.0 and 1.3.1 that may explain this regression is a pyOCD update:
1.3.0 is bundled with pyOCD 0.27.0
1.3.1 is bundled with pyOCD 0.27.3
All python tools bundled with Studio are accessible from the built-in terminal (Using tools in the terminal - Using tools in the terminal | Mbed Studio Documentation). That includes pip. You can downgrade pyOCD version included in Studio by running the following command in the terminal:
pip install pyOCD==0.27.0
b) Mbed Studio 1.3.0 is still available for download. We always keep at least 2-3 previous versions. Windows version can be found here: https://studio.mbed.com/installers/latest/win/MbedStudio-1.3.0.exe
Please only keep in mind that Mbed Studio has auto-update enabled. It means that 1.3.0 version will be automatically updated to 1.3.1. You can find information on how to disable auto-update in this post: Mbed studio 1.2 won't detect platform - #17 by arekzaluski
Thanks,
Arek - Studio team