I have fixed this problem but wanted to document the problem/solution for others hitting the same issue:
The desktop app suddenly no longer opened in Windows. No updates were done recently, nor have any databases been modified. Restarting windows did not resolve it.
Resolution:
I checked the log file (at C:\Users\xxxx.Neo4jDesktop\log.log in my case) and found:
. . .
[2021-10-07 08:04:36.954] [error] App initialization error: SyntaxError: Malformed JSON in file: C:\Users\klaus.Neo4jDesktop\persist\notifications.json
Unexpected token in JSON at position 0 {
constructor: 'SyntaxError',
stack: 'SyntaxError: Malformed JSON in file: C:\Users\klaus\.Neo4jDesktop\persist\notifications.json\n' +
'Unexpected token \u0000 in JSON at position 0\n' +
' at FileAsync.parse [as deserialize] ()\n' +
' at C:\Program Files\Neo4j Desktop\resources\app.asar\node_modules\lowdb\adapters\FileAsync.js:41:35\n' +
' at async C:\Program Files\Neo4j Desktop\resources\app.asar\dist\main.prod.js:1:88347\n' +
' at async z (C:\Program Files\Neo4j Desktop\resources\app.asar\dist\main.prod.js:1:100757)'
}
Removing (renaming) the trouble file notifications.json in the persist directory resolved the problem.
Desktop now opens again without problems and created a new notifications.json file.
