In Rhino8 when I open the first time a plugin-panel everthing works. Closing the panel and reopening leaves the panel empty. This is different to the behaviour in Rhino7 where everything works as expected.
Can you share code that we can run to see what is causing this?
I have 2 plugins brickdesign and sphereneRHINO behaving in the same way on Rhino8 vs Rhino7, both use IronPython as the gui - Generator. Both use Python code embedded in the c# wrapper. While BrickDesign uses WPF sphereneRHINO uses Eto. In sphereneRHINO I have a c# register function which is called from object_editor.py:
sphereneRHINOPlugin.cs (6.0 KB)
object_editor.py (17.5 KB)
I could try to recreate a toy plugin but it is a bit of work.