ID:10002 Can't open VHDL or Verilog HDL file "<name>"

CAUSE: The Quartus Prime software cannot open the specified VHDL or Verilog HDL file. This message can occur if you spell the file or path name incorrectly, the file name does not have the required extension, the file does not exist, or the file is in a directory that is not the project directory or a user library.

ACTION: Make sure that the VHDL or Verilog HDL file exists and has the correct file and path name. If the file is in a directory that is not the project directory, specify the directory as a user library.