Problems with HDL Coder, 64QAM and Zedboard

I am trying to run the 64QAM HDL Coder example "commqamtxrxhdl" on a Zedboard and the HDL Workflow Advisor gives me the following error message:

Failed Complex port type is not supported when the input parameter 'Target Platform' is set to any FPGA board. Please update the data type on outport ''commqamtxrxhdl/QAM Tx HDL/Pipeline5/' '.

How do I change the input parameter to something that works? When I look inside the "QAM Tx HDL" model, I see that the output of the RRC filter is set to fixdt(1,16,15). That does not sound like a complex value to me.

I have the same issue with the "QAM Rx HDL" block. Here the HDL Workflow Advisor complains about complex data input.

Some help appreciated,

Arne