Rescan for plugins
The procedure for doing so depends on the DAW, but this usually means quitting the DAW and relaunching.
Note that in MacOS, clicking the red X in the upper left corner closes the window but does not quit. Instead, do one of the following:
- Click the DAW menu item > Quit
- Or, right-click on the dock icon and click Quit
Check the Channel Configuration
Make sure the channel configuration matches one that is supported by the plug-in. For example, the plug-in may support a Mono In > Stereo Out configuration but not Mono In > Mono Out. Check the plug-in's User Guide to see what configurations it supports.