After two weeks returning to my NR installation it just gives notification.warnings.undefined
On the debug panel I get:

14.8.2023, 11:09:19
msg : error
"TypeError: Cannot read properties of null (reading 'rev')"

After removing all flows the notification.warnings.undefined still persists!
Any help for this?
The installation is on a RPI and was working without problems before.

What version of Node-RED and Node JS are you running?

14 Aug 11:21:15 - [info] Node-RED Version: v3.0.2
14 Aug 11:21:15 - [info] Node.js Version: v16.19.1

Try this: In the editor, go to the sidebar -> Context Data and see if there are any unused items. If so delete them and do a deploy.

Did it, found two of them, but problem not solved. Deploy gives:

Seems there is a problem with the storage
ENOSPC: no space left on device, copyfile ....

So, back to the roots :face_with_open_eyes_and_hand_over_mouth:

See you later, thanks ...