http://zorro-trader.com/manual/en/filter.htm
FisherInv(var* Data): var
does not match signature
FisherInv(var* Data, int TimePeriod): var
at top of indicators.c
// Inverse Fisher Transform
var FisherInv(var* Data,int Period);

but later it is defined as
var FisherInv(var* Data)
{

Looking closely, the Period arg is pointless. But without it you get a compiler error.

You might want to add this to bit of static analysis to your release steps
$ grep '^var' include/indicators.c | tr -d ';' | sort | uniq -c
all counts should be "2".

You're right in all points - this will be fixed in the next update.

You can fix this by editing indicators.c and removing the "int Period" from the function prototype.