Failed to register onCustomEditor:vscode.markdown.preview.editor

[jeluard]

Bug Description:

When using latest vscode/markdown builtin plugin, I get the following message:

root ERROR [hosted-plugin: 58828] Unsupported activation events: onCustomEditor:vscode.markdown.preview.editor, please open an issue: https://github.com/eclipse-theia/theia/issues/new

Steps to Reproduce:

1. Add "vscode-builtin-markdown": "https://open-vsx.org/api/vscode/markdown/1.54.1/file/vscode.markdown-1.54.1.vsix", to plugins
2. Start theia

[vince-fugnitto]

@jeluard which version of the framework are you using? It should be supported thanks to #8910 (next)
Can you verify using master?

[jeluard]

Indeed, it's fixed on master

[vince-fugnitto]

Indeed, it's fixed on master

It should be in the next release at the end of the month ~25th (or you can use next tag).