IDE 1.8.4 not launching on Win8.1/64

Suddenly arduino ide (1.8.3) does not run. So I uninstalled and reinstalled (1.8.4). But it still does not run.
Here is the result of debuging. Please Help!

Do you have any 3rd party hardware packages installed (File > Preferences > Additional Boards Manager URLs)?

pert:
Do you have any 3rd party hardware packages installed (File > Preferences > Additional Boards Manager URLs)?

he cant launch his ide so theres no way he can get to that.

could it be related to java version?

gledel

I had issue where splash screen would come up and then crash/disappear.
Is that the behavior your seeing?

If so, chase down previous thred about simply deleting folder:
c:\users\XXXXX\AppData\Local\Arduino15

After hours of trying also sorts of ideas re Java, etc, just singularly deleting folder and restarting the IDE worked.

Gary

tzijie:
he cant launch his ide so theres no way he can get to that.

I realize that but likely they would remember adding a 3rd party Boards Manager URL. The menu path I mentioned was just to explain what I was talking about.

GaryiLyons:
If so, chase down previous thred about simply deleting folder:
c:\users\XXXXX\AppData\Local\Arduino15

Yes, this is likely the solution. However, it would be nice to track down the actual source of the error, which I suspect to be an invalid character in a 3rd party hardware package's Boards Manager JSON file. If that is the case and I can reproduce the problem I'll try to get that fixed so it doesn't affect others.

pert:
Do you have any 3rd party hardware packages installed (File > Preferences > Additional Boards Manager URLs)?

Yes. I have additional Boards Manager URLs for esp8266 board.

I deleted the folder(c:\users\XXXXX\AppData\Local\Arduino15). Arduino runs!!

Thanks a lot! Excellent!!

I have esp8266 also and can't reproduce the problem so I think it will be safe to install that again (your preferences and installed boards were all lost when you deleted the folder). It's been over a year since the last ESP8266 core release so I don't think they would have recently added an invalid character. It's possible there was a temporary problem with one of the official Arduino package index files for Boards Manager or Library Manager or maybe something went wrong during the download and the file was corrupted.

GaryiLyons:
gledel

I had issue where splash screen would come up and then crash/disappear.
Is that the behavior your seeing?

If so, chase down previous thred about simply deleting folder:
c:\users\XXXXX\AppData\Local\Arduino15

After hours of trying also sorts of ideas re Java, etc, just singularly deleting folder and restarting the IDE worked.

Gary

Thanks, it worked