I tried all the combinations :
32bits plugin with Cubase in 32 bits mode -> freezes
64bits plugin with Cubase in 64 bits mode -> freezes
32bits plugin with Cubase in 64 bits mode (vst-bridge) -> works
the problem occurs if the plugin window is open when the plugin is removed
it occurs with your JuceDemoPlugin, I don’t add a new DialogWindow or anything else
it occurs when the last instance is removed and if you have clicked in the plugin window
It’s very strange :
insert 2 instances of JuceDemoPlugin, move all the parameters, remove both plugins, there is no problem
now insert 2 instances of JuceDemoPlugin, move all the parameters, remove one plugin, click in the window of the remaining plugin, remove it, Cubase freezes