Go to your app data folder in Windows (C:\Users\[Your Username]\AppData\Local). If you can't find it, make sure you can see hidden folders.
Delete the folder "nwjs".
Go inside the folder 'C:\Users\[Your Username]\AppData\Local\User Data\Default". Look for the files "Web Data" and "Web Data-journal". Delete these two files.
i followed this and it works now.
the problem can be caused if you launched a game with a newer version of NW.js
