When I launched ISim from the ISE design tools, the following error appears:
"ERROR:ProjectMgmt:387 - TOE: ITclInterp::ExecuteCmd gave Tcl result 'error copying "<my_proj>/simulation/behavioral/elaborate" to "<EDK_Proj>/ise/elaborate": file already exists"
The cause of this error is a mismatch between the project location and the working directory of ISE project setting. After changing the directories to the same directory, then the error was solved.
If an EDK component is present and the working directory is different from the project location directory, then ISIM will not launch.
This is a variation of the working directory/project location directory issue, but in this case the auto-generated scripts are putting the files in the wrong place.
This issue will be resolved in ISE Design Suite 14.6.