When creating a design with modules defined in the library "XilinxCoreLib", modules are not recognized when "Automatic Compile Order" is selected by right clicking in the design hierarchy tab.
Vivado does not support direct instantiation of modules from the "XilinxCoreLib" library name.
"XilinxCoreLib" is a legacy reserved library name and should not be used in Vivado due to potential conflict with legacy cores.
A warning message was added in Vivado 2014.2 to clearly indicate that this is not supported.
To resolve the issue, change the "XilinxCoreLib" library name to a new name that is not a reserved word.