This might help
If you encounter issues where VST instruments are opening as a Sampler Channel and not responding to input they are probably missclassified as Effects plugins. The Channel Rack hosts Generator (instrument) plugins, to avoid these Generator plugins from opening as Effects in the Mixer you must do the following:
Select 'Options > Manage plugins'.
Within the Plugin Manager select the following options:
'Rescan previously verified plugins'
'Rescan plugins with errors'
After the scan is completed, your plugins should now be properly identified as Generators and should no longer open as Effects plugins.
If the above solution doesn't work you may need to remove associated plugin database entries containing old information about the plugin(s):
From the FL Studio Browser, locate the entry for the plugin you're having issues with in 'Plugin database > Generators' and 'Plugin database > Effects'.
If the plugin entry is present right-click it and select 'Delete file...'.
Once you've confirmed the plugin entry is no longer present in either of the aforementioned locations, load the plugin from the Browser in 'Plugin database > Installed > Generators > VST' to confirm that it loads as expected.
If the plugin opens correctly you can now manage the plugin using the Plugin Manager or 'More plugins...' window as usual.