Mbed studio 1.2 won't detect platform

Just update to 1.2, and now I can compile but not Run a program!!!

It is greyed out, and clicking says “Connect a platform to run”

How do I revert to previous release without losing my files?

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Hi @roberthewitt,

Would you mind answering a few questions?

  1. What system are you on (Windows, Linux, Mac)?
  2. What board can no longer be detected?

Arek - Mbed Studio team

  1. Windows

  2. Mbed LPC1768

That was a prompt reply!

It was working before I upgraded, so if it is a new bug, I’d like to be able to revert to the old Studio

Thank you. We will take a look at it today. There are small changes in 1.2.0 for targets discovery but it shouldn’t affect this board.
Unfortunately it is impossible to downgrade to version 1.1.0. Mbed Studio has a built-in functionality for auto-update and the latest version is always downloaded & installed if network connection is present on the system. You can download and install an older version but it will be automatically updated on Studio restart. It was a decision we made some time ago. It is possible however that we can revisit it in the future.
In the meantime would you mind sending us logs? Please use Menu->Help->Report an Issue. This will help us investigating this issue on your system.

Arek - Mbed Studio team

That doesn’t sound good. So I need to save my files, uninstall then install 1.1?

Where are the logs?

You can see a direct link to logs in Menu->Help->Report an Issue dialog.
Uninstall of Mbed Studio does not remove your workspace with your programs. It only removes:

  • Mbed Studio application
  • Tools shipped with Mbed Studio

Arek - Mbed Studio team

My Mbed Studio has just auto updated (Linux OS), and all working great but if I had a problem like say the above I would not be able to use the Menu->Help->Report an Issue feature as it requires a Unix Mailspool (Movemail) or a Newsgroup Account. So have been wondering for a good while now… what’s wrong with compressing and POST’ing the data directly.

I just wanted to chip in to say that I’m experiencing the same thing following the update to 1.2.0. Also with the LPC1768 on Windows.
Normally when I plug in the mbed board, mbed Studio opens up a serial comms window that I use for debug output, but this isn’t happening. Even trying to open serial comms manually in mbed Studio fails (PuTTY is OK).

Hi @roberthewitt, @crobinson44

Thank you for reporting this issue and apologies for it. We can reproduce this issue. As far as we can tell it is limited to LPC1768 board and Windows platform. It is a regression in 1.2.0 version released today and is due to special cmsis-dap interface firmware that is present only on this board. We will try to release a patch release of Studio - 1.2.1 as soon as possible. Apologies for the inconvenience.

Arek - Mbed Studio team

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[2020-08-24T15:59:11.038] [DEBUG] MbedStudio - [mbs-plugin-common-mbed] An error occurred reading custom targets from custom_targets.json: not_found []

Mean anything?



(Attachment mbed-studio.log is missing)

Hi @arekzaluski,

Thanks a lot for the prompt response - I’m glad to hear it’s identified and patchable. :+1:

All the best,

1st try:

Unfortunately some attachments in your email message to [“mbed+49b13d65766165f2d5abc97a51275b8e@discoursemail.com”] (titled RE: [[Mbed Studio] Mbed studio 1.2 won’t detect platform) were rejected.

mbed-studio.log: Sorry, the file you are trying to upload is not authorized (authorized extensions: jpg, jpeg, png, gif, heic, heif).

If you believe this is an error, contact a staff member.

(Attachment mbed-studio.log.txt is missing)

The log keeps getting rejected, even when I change to .txt

Do you mind saying what the"special cmsis-dap interface firmware" is? I have never got debugging to work with this board

Do we know when a patch will be available? If I go back to 1.1.0, every time I exit, it upgrades(sic) to 1.2.0 which doesn’t work with my board!

I now have an impossible situation:

  1. Studio 1.2 won’t work with my board
  2. Going back to 1.1, python needs updating or it doesn’t work
  3. After updating Studio has to be restarted
  4. Restart goes to 1.2


Hi @roberthewitt

We understand the problem and are implementing a fix. As we suspected this issue is limited only to LPC1768 on Windows platform. A new patched version of Studio should be available till the end of this week.

As I mentioned above it is not possible to postpone indefinitely an auto-update of Studio from the UI (it was a decision we made). That being said until this issue is resolved you can disable auto-update by following these steps:

  1. Uninstall Mbed Studio 1.2 (your workspace with programs will not be removed)
  2. Install Mbed Studio 1.1 (you can still find it at https://studio.mbed.com/installers/latest/win/MbedStudio-1.1.0.exe)
  3. At the end of installation please deselect an option to start Studio
  4. Navigate into Mbed Studio installation folder (on Windows default installation folder for the current user is in ~\AppData\Local\Programs\Mbed Studio)
  5. Rename app-update.yml file inside resources folder to any other name
  6. Start 1.1.0 version of Studio

After following steps above your Studio IDE will no longer have auto-update enabled. I recommend disabling it only temporary as you will be missing new features in the future! To enable it back simply rename the file back to app-update.yml.

LPC1768 interface
As you know Mbed Studio and Mbed tools support multiple interface firmwares. Two popular ones are:

mbed LPC1768, however, is using a unique firmware that hasn’t been updated for some time. That’s why you see quite many issues with deploying and debugging on this board. We are currently working on updating the firmware on this board. It should resolve some of the issues and potentially bring new functionalities in the future (like webUSB, present in DAPLink).

Once again apologies for the inconvenience.

Kind Regards
Arek - Mbed Studio team


Just update to 1.2, and now I can compile but not Run a program!!!

If there is MBED disk displayed in the file manager try to program your board using the drag&drop or copy&paste method (copy the binary from the build folder and paste it to the MBED disk). This method is used to program the board when building with the online compiler. Make sure you push and release the RESET button to run the new program.

Best regards, Zoltan

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Yes. Zoltan is correct. Drag and drop of the binary should still work correctly. Unfortunately, to enable serial monitor you will have to either downgrade to version 1.1.0 or wait a little bit longer for a 1.2.1.

Arek - Mbed Studio team

Thanks for all the very good advice.

Now all I need is someone to fix my other problem: