HDL:Compiler:104:104 - "path" Line XXX: Cannot find in library

So you typically get this error when importing an EDK created core into the ISE. You need to have the design include these libraries, to do this do:

1. Go to the  <Libraries> Tab
2. Type in the exact Library Name
3. in the Library Files location you actually need to go there, it will look something like /path/to/EDK/hw/XilinxProcessorIPLib/pcores/proc_common_v2_00_a/hdl/vhdl/
4. It should find all the files and you are good to go