Go to Options > File Settings > Manage Plugins. Check "Verify Plugins" and click "Find More Plugins."
Here is the step-by-step process to install or reinstall the WaveShell-VST3 9.91_x64:

Go to Options > File Settings > Manage Plugins. Check "Verify Plugins" and click "Find More Plugins."
Here is the step-by-step process to install or reinstall the WaveShell-VST3 9.91_x64: