I created a notebook and after creating tasks inside appeared notes 1 day apart with the title "Eroor!" and inside "Notebook is missing in the Settings".
Help > About > Copy will provide a full list of plugins and their versions that can be pasted here. That's why the support template you initially completed asked for it.
Hmm can't really tell which one it is from the eroor message, and somehow GitHub returns 342k results for "eroor". You could try to disable the plugins one at a time, but since it's a note that the plugin already created I'm not sure it would help.
The next thing would be to check the source code of all these plugins.