Arduino IDE 1.8.6 not starting. My Arduino IDE is not getting started. It just crashes before opening up. I don't know what the problem is. It was working well enough before without any issues. 

This is what I see after running the arduino_debug.exe in the command line



Note: I added a library (DHT) to work with my humidity and temperature sensor and since after then, this issue comes up. I tried to reinstall it like more than 7 times, but the issue still persists.

Please help me with it. Thanks.
The cause of the problem is that you have a corrupted library index file. The solution is to delete the file, which will force the Arduino IDE to download a (hopefully) uncorrupted fresh version from the Internet:


Open the C:\Users\JK\AppData\Local\Arduino15 folder
Delete the file library_index.json
Try starting the Arduino IDE again




For anyone encountering this problem who is using an operating system other than Windows, the location of library_index.json is different:

On Linux:

/home/{username}/.arduino15 (a.k.a. ~/.arduino15)

On macOS:

/Users/{username}/Library/Arduino15

If using the Arduino IDE in portable mode:

{Arduino IDE installation folder}/portable



The issue of a corrupted library index file preventing the Arduino IDE from starting has been reported to the Arduino developers and they are already working on a fix:

https://github.com/arduino/Arduino/issues/7937