Language shown as "not deployed" even if it is present in MPS 2024+?

[malueck]

When creating a fresh project in a minimum installation on MPS2024.1.1 with the org.iets3.os.core plugin, and its minimal dependencies, some languages of the plugin fail to be deployed.

For example, the language org.iets3.os.expr.lambda claims that org.iets3.os.expr.base is not deployed and shows an error in the Modules Pool, even with org.iets3.os.expr.base shown above it and loaded without errors.

I reported this also to MPS as but it seems not clear if this is an issue with the plugin or with MPS.
Link: https://youtrack.jetbrains.com/issue/MPS-38155/Languages-from-plugin-are-not-acknowledged-as-deployed
Maybe you have an idea?

[malueck]

This issue was not present when the plugin is loaded in MPS 2023.2, so it can be caused by the Modules Pool / Project Panel UI rewrite that has been done in MPS 2024.1, but to me it is not clear why that would cause it either.