Can't open Arduino anymore on mac Big Sur

Hi--I am on a macbook pro and as recently as a few weeks back, I was able to use the Arduino app. However, today I tried to open it, and while the initial window pops up and goes through "Initializing Packages" and "Starting", the app never opens after that.

I am on macOS 11.4 (Big Sur) (which admittedly updated fully today, but I was on an earlier version of Big Sur a few weeks back, and Arduino ran fine). I've tried a few different version of Arduino at this point:
--Arduino IDE 2.0.0 beta (this had a different result--see below)

I've updated my Java and JDK. I've tried to follow the steps in this thread below, but I don't even find the file that is suggested to be edited. I've tried emptying out the contents of the Arduino15 folder (except preferences.txt). I've restarted my computer multiple times.

NOTHING WORKS! Each time I just get the attempted startup, and then nothing. The only thing that sort of comes close to opening the app is going into the packages folder and clicking on the MacOS Arduino Unix executable file (which launches the terminal). Then a few of my recent sketches open up in arduino, but I can't open anything else.

For Arduino IDE, when I open that, I keep getting just one sketch file opening, and I can't create or open another in the same app.

Help? I'm not a sophisticated user, so please if you have any advice, make it really basic and step-by-step. I know I can use the online version, but I really would like to get the app to work on my mac.

(PS I have the same conditions on my other MacBook pro--same OS, updated Java, Arduino 1.8.13, and it all works fine. Not sure what the difference is here!!)


Please provide a detailed description of what you mean by that. What happens when you attempt to open something else? If there is an error message, please post the full and exact message.

So when I try to open Arduino or any arduino sketch, the initialization/welcome window pops up (the one with the logo and the little doodles and the attributions). At the bottom, it says "Initializing packages...." then after a while, that message changes to "Starting..." and then after that, the app closes.

PS I do have the same configuration on my other mac (OS 11.4, Arduino 1.8.13, updated Java) and it works completely fine. So not sure what the difference is here.

Please do this:

  1. Open your Applications folder.
  2. Open Utilities.
  3. Double-click on "Terminal".
  4. Type open Arduino
  5. Press Enter
  6. Wait for the Arduino IDE to finish starting, or failing to start. If it starts, attempt to open a sketch, or whatever action it is that causes the failure.
  7. Switch back to the terminal window if the Arduino IDE window took the focus.
  8. Press Cmd+A. This will select all the text in the terminal window.
  9. Press Cmd+C. This will copy the selected text to the clipboard.
  10. Open a forum reply here by clicking the Reply button.
  11. Click the </> icon on the post composer toolbar. This will add the forum's code block markup (```) to your reply to make sure the error messages are correctly formatted.
    Code block
  12. Press Ctrl+V. This will paste the compilation output into the code block.
  13. Move the cursor outside of the code block markup before you add any additional text to your reply.
  14. Click the Reply button to post the output.

Hopefully that will give us some information we can use to help you with the problem.

1 Like

Hi--so I actually solved the problem by completely uninstalling Arduino (including the app, the Arduino15 folder and the sketchbook folder), then emptying the trash. Then I chose to install Arduino 1.8.13 since I know that one works on my other Mac with OS Big Sur. Seems like that solved my problem. Something must have gotten corrupted in the old installation.

I'm glad to hear it's working now. Thank you for taking the time to post an update. Enjoy!