I seem to keep getting this error below, despite being told that all parameters are floats;

Runtime Error: Trying to perform a summation, subtraction, multiplication or division between 'float' and 'decimal.Decimal' objects throws a TypeError exception. To prevent the exception, ensure that both values share the same type.
at TradePutOption
self.takeProfitTicket = self.LimitOrder(self.put in main.py:line 71

TypeError : unsupported operand type(s) for *: 'float' and 'decimal.Decimal' (Open Stacktrace)

I think the issue is this code - what am I doing wrong?

# set Take Profit order
self.takeProfitTicket = self.LimitOrder(self.put, 1, round(ticket.AverageFillPrice * d.Decimal(0.5), 2))