[Problem] MPF crashes each time, when parameters are empty and checkbox is unticked

[Feathered-Serpent]

Before You Submit

• Remember to try the latest WIP build to see if the issue has already been addressed.
• Is it copy protection related? If so, report the issue here instead.
• .NET 6.0 has known issues, please try using another build to reproduce the error
• Check multiple discs to help narrow down the issue
• Check the Options to see if changing any of those affects your issue.

If all of those fail, then continue...

Version

• Stable release (Version 2.4-c4ef14ea)
• WIP release (Version 2.4-1e55b8b8)

Build
What runtime version are you using?

• .NET Framework 4.8 running on Windows 10 Pro 21H2
• .NET 6.0 running on (Operating System)

Describe the issue
When the parameters field is empty and you uncheck the checkbox, MPF crashes

To Reproduce
Steps to reproduce the behavior:

1. select No system selected on the System/Media Type
2. Click on the checkbox right of the Parameters (which would be empty at this point)
3. Click on the checkbox again
4. MPF crashes

Expected behavior
Nothing should happen (except the parameters field becomes visible-only again)

[mnadareski]

@Feathered-Serpent please try the latest WIP based on the frontend-over branch. See if that fixes your issue.