Hi everyone.. my Arduino IDE 1.8.6 just stopped working all the sudden. It was working great before and i have done so much work with it, but suddenly it stopped working. When I click on the program icon, it just shows the start window underneath says initializing packages and then preparing boards, and then immediately disappears and nothing happens. I tried to run the program as an administrator, reinstall the program, download the hourly build portable software, and I was not successful.
When I run the Arduino debug it shows "error parsing library.index: unexpected end-of-input in value_string" and a bunch of text follows.
Currently I am using the online coding tool which is OK but I really need to get my program working. By the way I am using Windows 10 (64-bit).
You have a corrupted library index file. The solution is to remove your local copy of the file, which will force the Arduino IDE to download a fresh (and hopefully uncorrupted) version of the file from the Internet:
Open C:\Users{your user name}\AppData\Local\Arduino15. This is under a system folder that Windows normally hides. You can set Windows Explorer to show hidden folders via View > Hidden Items (check).
Rename library_index.json to library_index.json.txt
Click the "Reply" button on this forum thread.
Click "Attachments and other options".
Click "Browse..."
Select C:\Users{your user name}\AppData\Local\Arduino15\library_index.json.txt
Click "Open"
Click "Post"
Start the Arduino IDE.
Adding the .txt file extension causes the IDE to no longer see it as library_index.json and also allows the file to be attached on the Arduino Forum (it only allows certain file extensions). The reason I'm requesting you to attach the corrupted library_index.json file is because you're the second person who's reported this problem in the last couple days and I've never seen this problem in years before this. There is currently an issue report submitted to Arduino and being able to look at the actual corrupted file might be helpful to find out what's going on:
Thank you very much for the reply. I followed the steps you mentioned and now my IDE is working like a charm. I tried to attached the (library_index.json.txt) file but its size is more than 5MB. Do you suggest another way so I can share it with you?
I'm glad to hear it's working now. Thanks for your willingness to assist in the investigation of this problem! I'll private message you my email address and hopefully you can send it to me via that channel.