@CrossRoads & WaWa
Thanks guys. Your posts solved it for me. I'm now afraid to close my IDE. Took some time to find your solution and I'm glad you posted it!
This works fine. Thank you.
Grazie mille!
i have had the same issue on my mac with arduino not opening however i can't or the life of me find the library folder to delete these files... its not under my user. There are no grey folders to click on what so ever. Can anyone help as to where else it might be located or how to find it. thanks
First of all, I am not good at English. I'm sorry if I used the wrong word or grammar.
I was using Arduino until yesterday. Suddenly, this is not executed. So I turned the laptop back on, deleted Arduino, and re-installed it. I can't execute Arduino. Is there a solution to this problem?
Hello,
Long time user first time poster.
I began having problems with the IDE yesterday (was 1.8.5). (crashing at start up)
In the end I uninstalled and removed everything and installed 1.8.12, only to have the same issue every time I used the boards manager.
I found posts suggesting to use the hourly build, and this appears to have gotten over that hurdle and left me with a new one.
I can only compile once, without having to re-start the IDE.
(ei: it will not compile a second time without restarting the IDE)
I note that the contents of "C:\Users\e156994\AppData\Local\Temp\hsperfdata_E156994" is not accessible while the IDE is open (this may be a red herring, as the content get deleted when the IDE is closed).
I'm using Windows 10.
with Arduino 1.8.13 Hourly Build 2020/06/03 04:33
and the very simple BLINK project ...
I have attached two screen shots showing the successful compile and upload, followed immediately by the failed compile.
It is like the IDE has not fully 'let go' after the upload.
Disconnecting and re-connecting the Nano does not help. Only closing and re-opening the IDE.
The error log from the failed compile is reproduced here ...
Any thoughts would be much appreciated.
Best Regards,
Wit C.
Arduino: 1.8.13 Hourly Build 2020/06/03 04:33 (Windows 10), Board: "Arduino Nano, ATmega328P"
C:\Program Files (x86)\Arduino\arduino-builder -dump-prefs -logger=machine -hardware C:\Program Files (x86)\Arduino\hardware -tools C:\Program Files (x86)\Arduino\tools-builder -tools C:\Program Files (x86)\Arduino\hardware\tools\avr -built-in-libraries C:\Program Files (x86)\Arduino\libraries -libraries C:\Users\e156994\Documents\Arduino\projects\libraries -fqbn=arduino:avr:nano:cpu=atmega328 -vid-pid=1A86_7523 -ide-version=10813 -build-path C:\Users\e156994\AppData\Local\Temp\arduino_build_641548 -warnings=all -build-cache C:\Users\e156994\AppData\Local\Temp\arduino_cache_587543 -prefs=build.warn_data_percentage=75 -prefs=runtime.tools.avrdude.path=C:\Program Files (x86)\Arduino\hardware\tools\avr -prefs=runtime.tools.avrdude-6.3.0-arduino17.path=C:\Program Files (x86)\Arduino\hardware\tools\avr -prefs=runtime.tools.avr-gcc.path=C:\Program Files (x86)\Arduino\hardware\tools\avr -prefs=runtime.tools.avr-gcc-7.3.0-atmel3.6.1-arduino5.path=C:\Program Files (x86)\Arduino\hardware\tools\avr -prefs=runtime.tools.arduinoOTA.path=C:\Program Files (x86)\Arduino\hardware\tools\avr -prefs=runtime.tools.arduinoOTA-1.3.0.path=C:\Program Files (x86)\Arduino\hardware\tools\avr -verbose C:\Users\e156994\Documents\Arduino\Projects\MyBlink\Blink\Blink.ino
C:\Program Files (x86)\Arduino\arduino-builder -compile -logger=machine -hardware C:\Program Files (x86)\Arduino\hardware -tools C:\Program Files (x86)\Arduino\tools-builder -tools C:\Program Files (x86)\Arduino\hardware\tools\avr -built-in-libraries C:\Program Files (x86)\Arduino\libraries -libraries C:\Users\e156994\Documents\Arduino\projects\libraries -fqbn=arduino:avr:nano:cpu=atmega328 -vid-pid=1A86_7523 -ide-version=10813 -build-path C:\Users\e156994\AppData\Local\Temp\arduino_build_641548 -warnings=all -build-cache C:\Users\e156994\AppData\Local\Temp\arduino_cache_587543 -prefs=build.warn_data_percentage=75 -prefs=runtime.tools.avrdude.path=C:\Program Files (x86)\Arduino\hardware\tools\avr -prefs=runtime.tools.avrdude-6.3.0-arduino17.path=C:\Program Files (x86)\Arduino\hardware\tools\avr -prefs=runtime.tools.avr-gcc.path=C:\Program Files (x86)\Arduino\hardware\tools\avr -prefs=runtime.tools.avr-gcc-7.3.0-atmel3.6.1-arduino5.path=C:\Program Files (x86)\Arduino\hardware\tools\avr -prefs=runtime.tools.arduinoOTA.path=C:\Program Files (x86)\Arduino\hardware\tools\avr -prefs=runtime.tools.arduinoOTA-1.3.0.path=C:\Program Files (x86)\Arduino\hardware\tools\avr -verbose C:\Users\e156994\Documents\Arduino\Projects\MyBlink\Blink\Blink.ino
Using board 'nano' from platform in folder: C:\Program Files (x86)\Arduino\hardware\arduino\avr
Using core 'arduino' from platform in folder: C:\Program Files (x86)\Arduino\hardware\arduino\avr
Detecting libraries used...
Error compiling for board Arduino Nano.
Thanks, deleting the "C:\Users\XXX\AppData\Local\Arduino15" folder worked for me too!
Ron47Walker:
Thanks, deleting the "C:\Users\XXX\AppData\Local\Arduino15" folder worked for me too!
I am glad you didn't format C:
only one file in this folder and one subfolder should be deleted
My computer crashed and after fixing this I decided to upload the new IDE (ver 12). After deleting the old version I uploaded ver 12. All seemed to go well but when I tried opening the program from start, it displayed the opening screen (with all its squares) for a few moments which then vanished.
I remember some years back that I had the same problem and one of your people walked me through the fix which involved deleting some files. I can't remember the procedure. Can you help me get my arduino working again?
Thanks johnell
안녕하세요!
[C:\Users(사용자명)\AppData\Local]의 경로에 'Arduino15'라는 폴더가 있습니다.
IDE를 실행하시기 전에 삭제하고서 진행하시면 실행됩니다.
다만 이 방법은 실행할 때마다 계속 진행해야 하는 임시적인 해결책일 수도 있습니다.
pilcjas:
i have had the same issue on my mac with arduino not opening however i can't or the life of me find the library folder to delete these files... its not under my user. There are no grey folders to click on what so ever. Can anyone help as to where else it might be located or how to find it. thanks
I believe the folder is hidden. You will need to configure Finder (I believe that's what it's called on Mac) to show hidden folders.
You're welcome. I'm glad to hear it's working now. Enjoy!
Per
There was a problem with Arduino's package_index.json file used for Boards Manager that caused the NullPointerException error and prevented the IDE from starting.
Now the package_index.json file has been fixed, but to recover the Arduino IDE to a working condition you must delete the bad package_index.json from your computer as well as the cache folder, then restart the Arduino IDE as usual.
Windows (regular IDE):
remove file C:\Users\YourUsername\AppData\Local\Arduino15\package_index.json
remove folder C:\Users\YourUsername\AppData\Local\Arduino15\cache
Windows (Microsoft Store app):
remove file C:\Users\YourUsername\Documents\ArduinoData\package_index.json
remove folder C:\Users\YourUsername\Documents\ArduinoData\cache
Mac:
remove file /Users/YourUsername/Library/Arduino15/package_index.json
remove folder /Users/YourUsername/Library/Arduino15/cache
Linux:
remove file /home/YourUsername/.arduino15/package_index.json
remove folder /home/YourUsername/.arduino15/cache
Arduino IDE in portable mode:
remove file {Arduino IDE installation folder}/portable/package_index.json
remove folder {Arduino IDE installation folder}/portable/cache
NOTE: These are in hidden folders. You will need to configure your file browser software to show hidden folders in order to see them.
Please note that the problem that caused the Arduino IDE to break from the bad package index file has already been fixed and will be in the next release of the IDE. That's the reason why the Nightly/Beta Builds are not affected, and also the reason why we did not detect this problem earlier.
Sorry for any inconvenience this has caused!
I have uninstalled Arduino, deleted the Arduino15 folder and reinstalled Arduino and it opens Arduino well.
But... Now it won't let me save any projects 
Exception in thread "AWT-EventQueue-0" java.lang.InternalError: Should not get here
at sun.nio.fs.WindowsNativeDispatcher.GetFinalPathNameByHandle(Native Method)
at sun.nio.fs.WindowsLinkSupport.getFinalPath(WindowsLinkSupport.java:77)
at sun.nio.fs.WindowsLinkSupport.getRealPath(WindowsLinkSupport.java:242)
at sun.nio.fs.WindowsPath.toRealPath(WindowsPath.java:836)
at sun.nio.fs.WindowsPath.toRealPath(WindowsPath.java:44)
at processing.app.BaseNoGui.saveFile(BaseNoGui.java:897)
at processing.app.SketchFile.save(SketchFile.java:287)
at processing.app.Sketch.save(Sketch.java:138)
at processing.app.SketchController.save(SketchController.java:352)
at processing.app.Editor.handleSave2(Editor.java:1900)
at processing.app.Editor.access$1000(Editor.java:117)
at processing.app.Editor$11.run(Editor.java:1880)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
at java.awt.EventQueue.access$500(EventQueue.java:97)
at java.awt.EventQueue$3.run(EventQueue.java:709)
at java.awt.EventQueue$3.run(EventQueue.java:703)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:74)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:205)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)
Hey,
I had same problem, that i just try start IDE, it shows "Initialize packages" and it turned off.
I FIND OUT!!!!
that u need to go to [C:\Users\ComputerName\AppData\Local, find Arduino15 folder, delete it and re-install arduino.
if you can't find AppData, just find upper "file,home,share,view", press on view and check on "hidden items" box.
Because old application data of arduino still saved there, even if you re-install arduino.
and it worked form me!
Clean all the key of arduino from registry. I have faced with this issue then solve promlem like this.
hello
i have the same problem.
the last update on my PC was today with :
Security Update for Adobe Flash Player: June 9, 2020
your tips works perfectly. i delete the folder \arduino15 and install again the ide..Thanks.
Hi experts,
2020.06.11 1:00 pm
"package_index.json" seems again faulty.
But yesterday, after the first failure I did a backup. Cutting Internet connection and copying it back, I can continue.
Now at 3:00 pm I tried again with internet connection, after deleting "package_index.json" file and cleaning the Arduino15/cache but still upload break with error.
With my backup and without internet connection it works.
best regards
August
IDE 1.8.12.0 suddenly stoped working on Windows 7
I have been using this version of the IDE for sketches for a robot I am making. Every thing was fine 2 days ago but the next day IDE would not open. Failing on 'installing packages' I have de-installed and re-installed but still fails
amzr:
Hi experts,2020.06.11 1:00 pm
"package_index.json" seems again faulty.
But yesterday, after the first failure I did a backup. Cutting Internet connection and copying it back, I can continue.Now at 3:00 pm I tried again with internet connection, after deleting "package_index.json" file and cleaning the Arduino15/cache but still upload break with error.
With my backup and without internet connection it works.
best regards
August
the instructions have "delete the cache folder"
I deleted the Arduino15 folder, and the IDE still will not install.