ERROR Child node 'open-editors:root' does not belong to this 'open-editors:root' tree

Firstly,Complete project initialization by executing the command excute ‘yo theia-extension’,choose ‘backend-community’
Then run ‘yarn’ in sequence. Enter browser-app and run ‘yarn start’
Clicking ‘FILE’ and ‘NEW FILE’ will cause an error

Does anyone know the solution? Thank you very much。

@Dennis thank you for the discussion and reporting the issue!

I confirmed that I also experienced the problem using the generator, the issue is that the UntitledResourceResolver while used in core and the new file functionality is only ever bound in the plugin-system. Since the generator does not include the plugin extensions as dependencies the error will occur.

I’ve opened https://github.com/eclipse-theia/theia/pull/11195 to fix the problem :slight_smile:

Thank you for your response, but there still seems to be this problem. At present, the browser will report errors, and there is no error log on the backend. I wonder if there are other reasons?

@Dennis did you upgrade your application and extension to 1.26.0 which includes the fix?
I confirmed this morning with a minimal example such as one generated by ‘backend communication’ that new file works well: