It's clipping on the channel digital display
If your display is metering pre-fader, it's likely also metering pre-EQ and pre-insert and pre-compression. This means that the clipping is on the very first stage, your input, and no amount of compression will resolve the issue, because it's clipping ahead of the compressor. That would mean the input needs to be turned down.
You need to think about the signal flow, and where in the chain you are metering. You can't remove distortion; you can only prevent it.
If you haven't studied the extensive amount of literature on proper gain structure, now is a good time to start. There are many resources on ProSoundWeb, discussions in these fora, and elsewhere online dealing with proper gain structure. There's no need to go into that here, but it can be summarized as "maximize your gain early and often."
Disclaimer: I am not familiar with your board. I haven't read the manual or looked at a block diagram of it.