LAYERFILTEREXCESS system variable
Layer Filter Excess
Specifies the maximum number of layer filters allowed in a drawing before suggesting some be removed. You can create any number of layer filters. However, if the number of layer filters exceeds this value and exceeds the number of layers, a message dialog displays the next time you open the drawing. It recommends deleting all layer filters to improve performance. When set to 0, the message is never displayed.