Cannot read property 'id' of undefined

Hello, When I run the ‘yarn run start’ command to start the theia application I met with this problem, Is there anyone knows what’s going on and how to fix it?

@LamYunfu unfortunately I do not believe we’d be able to tell without additional information.
I see that you’re attempting to start a custom application, but it is not clear if there are any customizations from the application that contribute to the issue.

For example, if you are composing an application the following documented example (https://theia-ide.org/docs/composing_applications/) worked for me.

Thanks, I 'm just trying to upgrade the version of Theia in my Application. I am using version 0.8.0 for a long time and build a application runnable, maybe it’s too old so I can’t use some new features of Theia. Now I’m trying to upgrade it to the latest version 1.9.0. First, I just follow the Quick start guide, dowload the latest version and find that the the file structure is different from mine, Now the main code is under “examples” folder. Then I just migrate the extension written previously to the “examples” folder and run the “yarn start”, finally encountered such problem. So maybe the way I upgrade the Theia is wrong, Is there any better way to upgrade the underlying version of Theia of my application? Thanks.

Now I’m trying to upgrade it to the latest version 1.9.0. First, I just follow the Quick start guide, dowload the latest version and find that the the file structure is different from mine, Now the main code is under “examples” folder.

@LamYunfu this is not the recommended way to create a custom application and maintain it (as this is simply the source code of the framework with example applications for test purposes).

If you want to create your own IDE you should follow https://theia-ide.org/docs/composing_applications.

Thanks, So if I follow the composing_applications guide, the UI of the appliction seems come from a firmly old verison of Theia. I open the package.json file, it shows “latest”. Am I using the the latest version of Theia or the older version? Or is there any way or commad to know the exact version of Theia I am using now?

Yes, running yarn theia --version will show you which version of Theia you’re currently using. Also, you can check the yarn.lock file if you want to know the version of any dependency, including Theia packages.

Thanks.