SDRAM “altera_avalon_new_sdram_controller” IP is not included in new versions of Quartus Prime (it is until version 18), and Qsys project cannot be compiled if it contains it (even if the component IP is included in the /ip folder of the project).
Resolution
The “altera_avalon_new_sdram_controller” folder (may be obtained from a previous version of Quartus Prime/II) should be copied into the following directory:
<Quartus_Prime_directory>/ip/altera/sopc_builder_ip/altera_avalon_new_sdram_controller
