You may get this error message if your MAX PLUS II VHDL design resides in your PC root directory.
If this is the case, you should create a subdirectory for your design and move your design files into that newly created subdirectory. In general, Altera recommends that you maintain your design files in subdirectories.
You may also get this error if you are using a user-defined library and have not specified the project library name. This can occur if you have moved your files to a new directory. To correct the error, go to "Interfaces –> VHDL Netlist Reader Settings" (when the compiler window is open) and specify the library name and the directory where the user-defined library files are located.
Specifying the user library directory from "Options –> User Libraries" does not work for VHDL user libraries, since you cannot specify the VHDL library name.
In the library clause section, declare the library in the VHDL code as follows:
LIBRARY work;
USE work.parts.ALL;