In reply to chr_sue:
Meanwhile I found the problem. It si in the build_phase of your en.
function void build_phase(uvm_phase phase);
super.build_phase(phase);
//create agent
dma_agnt = dma_agent::type_id::create("dma_agnt", this); // this
//Create and build reg model
regmodel = dma_reg_model::type_id::create("regmodel");
regmodel.build();
//create adapter
m_adapter = dma_adapter::type_id::create("m_adapter"/*,, get_full_name()*/);
endfunction
This is now as it works.
Your mistake was here:
dma_agnt = dma_agent::type_id::create("dma_agent", this);
The component name and the component are different.
This is why it worked with dma_agent.
See here the solution.