Plugin problem

I’m trying to lay some FX across an audio file, and while some of the plugins work, many (not all) of them give me an error message - “Cannot handle the required number of input channels”. The Sonnox plugins also say “Plugin is switched off”.

I’ve been using these FX plugins successfully before, although this is the first session I’ve had with WL7 since I upgraded to 7.1

Any idea what the problem might be?

You need to give me details, eg. a specific example.