You may see this error while compiling a custom FIFO or a RAM block in the Intel® Quartus® Prime Software Standard or Lite versions for an Intel® MAX® 10 device.
This error is seen because Intel® MAX® 10 device compact variants do not support memory initialization. If you have not provided any mif file for your custom design and still see this error in Intel® Quartus®Prime Edition Software, it may be because a mif file is being inferred by the RTL coding style
Signal declaration for memory_type should be changed from
signal mem : memory_type :=(others => (others => '0'));
to
signal mem : memory_type;
This is to ensure that memory is not initialized and there is no compilation error in the Assembler stage.