Arduino 1.6.4 through 1.6.9 will not start on OS X 10.10.5

I have googled until my fingers bled and find references to this issue over time. Tried installing legacy Java etc but nothing changes. 1.6.3 loads fine. One thing I noticed is that I have nothing in Java/Extensions folder.

Is there an issue with having multiple versions of Arduino in Applications folder?

What info is needed to solve this or have I missed the secret recipe somewhere?


I don't know if this relates to your problem or not but it is worth a try:

A bunch of people have had IDE 1.6.x problems, including IDE crashes and bizarre compile errors, when they had a previous 1.5.x/1.6.x installation. At least some of those problems seem to be caused by out-of-date executables that the IDE saves outside the IDE installation directory. Perhaps that is what is causing your particular problem. In such cases it appears that the fix is to delete or rename the old "Arduino15" directory and re-install 1.6.x.

On Mac OS X: /Users/(username)/Library/Arduino15

On Windows: C:\Users(username)\AppData\Roaming\Arduino15

On Linux: /home/(username)/.arduino15 (a.k.a. ~/.arduino15)

I'm think your problem might be related to this item in the 1.6.4 release notes:

[ltr][color=#4f4e4e]* Windows and MacOSX: updated bundled JVM to 1.8.0_45 (latest available atm)[/color][/ltr]

Hey Johnwasser, I have a problem on my Mac El Captain when the Arduino program will not open, I have placed the Arduino.APP under the Macintosh HD/Application/ is that wrong, I cant find the program, I would say that it should be under root/Application/

regard Stefan

Hey Johnwasser, I have a problem on my Mac El Captain when the Arduino program will not open. I have placed the under the Macintosh HD/Application/. Is that wrong? I cant find the program? I would say that it should be under root/Application/.

Use the little magnifying glass near the top right corner of your screen to find the file. Drag it to the Applications folder.


Thank you. This worked!!! I found the Arduino15 folder and renamed it. Was then able to start 1.6.9. You are a genius. I can now move forward.