In reply to chr_sue:
I am not sure if that’s true. as far as I remember it was macro.
/uvm-1.2/src/reg/uvm_reg_model.svh:typedef bit unsigned [`UVM_REG_DATA_WIDTH-1:0] uvm_reg_data_t
uvm-1.1d/src/reg/uvm_reg_model.svh:typedef bit unsigned [`UVM_REG_DATA_WIDTH-1:0] uvm_reg_data_t ;
@Marc43 - you need to compile UVM source code with that define not your TB if that makes sense.