from the looks of that error, it seems you have placed the properties of this datablock outside of the curly braces {} < these
making a function? start and end it with curly braces, like this:
function harold(%this) {
echo("you called me!");
} //END WITH CURLY BRACES
Edit:
Your footprint particle datablock:
datablock PlayerData(defaultfootprintParticle){
diffuseMap[0] = "footprint";
vertColor[0] = true;
translucent = true;
castShadows = "0";
translucentZWrite = "1";
materialTag0 = "Player";
decalOffset = "1";
dustEmitter = "1";
footPuffEmitter = "1";
footPuffNumParts = "1";
footPuffRadius = "5.0";
};
Your function to call it (doing /dfprint)
function serverCmdDFPrint(%player) {
//do you want to assign this to the player here?
}
I can't seem to find the footprint add-on to see what you are trying to do, if you could link it here it would be easier.