Receiver on Wall Mount remote will not fit into canopy on Hampton Bay 547578 ceiling fan. Any solutions?

Is this a remote that came with the fan new? If so it should fit but it will be snug. Tell us more details. If it's a universal remote receiover you may need to buy from HB.

It's a Hampton Bay Wall Mount Universal Remote (191-707) that I purchased separately.

It should fit. I can't find your model fan, seems to have one too many numbers. Can you tell us the model name?

Hampton Bay Landmark Plus 42 in Ceiling fan model 547578

It should fit fine, the Landmark uses a standard canopy. Sometimes you have to be very creative, these things are not very well designed.