Remove default start event for ad-hoc subprocess(expanded) as in collapsed

[GeethaParthasarathy]

Describe the bug

When we create an expanded ad-hoc subprocess a start event is added to it as default just like in every other sub processes. But ad-hoc sub process does not allow events inside it and only allows task. This is the case when we directly create a collapsed ad-hoc subprocess where on drilling one level down we do not see any start event created by default.

Steps to reproduce

1. Create an expanded ad-hoc sub process
2. We could see that a start event is added by default and a lint error pops up for the user to remove the added start event
3. Add a collapsed ad-hoc sub process on drilling down we do not see a default start event added to it

Screen.Recording.2025-02-26.at.10.32.39.mov

Expected behavior

Remove default start event for expanded sub process so that the user need not have to remove them as part of the lint error displayed

Environment

• OS: [MacOS 10.2]
• Camunda Modeler Version: [5.33 rc-1]
• Execution Platform: [ Camunda 8]
• Installed plug-ins: [...]

Additional context

No response

[nikku]

Should absolutely be fixed, thanks for reporting. CC @jarekdanielak, maybe we can smoothen this in the near future?

[Buckwich]

Would it make sense to add an activity instead of the start event? Otherwise the linter complains about that missing (in camunda 8.7 and higher)

[barmac]

Would it make sense to add an activity instead of the start event? Otherwise the linter complains about that missing (in camunda 8.7 and higher)

Activity is a grouping term for multiple element types:

• tasks (blank, service, script... subtypes)
• subprocesses (ad-hoc, transaction, event...)

Which one would you choose and why?

In the case of a subprocess, it's clear because it can contain only blank start events.

[Buckwich]

I would have used a blank task as a starting default as its the first valid activity (i think gateway wouldn't make much sense). But I don't know if that would align with our users needs.
I think we should leave it empty then, ans the user needs to decide. That would also be consistent with the other variants (eg collapsed)