A project created or opened in Project Navigator 11.2 (or any version of ISE 11.x) should be able to be opened in any other ISE software 11.x version without needing to migrate or convert. However, if the device family used in the project is not available in an install version that a user chooses to open the project with, the following pop-up dialog is issued.
"Device not valid for this installation, do you want to open the project?"
If all of the following circumstances are true, the .XISE file will become corrupted and no longer be able to be opened in any version of ISE:
- The project was last open in Project Navigator 11.2 or later.
- The project is now being open in Project Navigator 11.1.
- The Project Device is not available in the ISE 11.1 install (e.g., Virtex-6 and Spartan-6 devices).
- The user selects "No" in the dialog box stating that the device is not valid.
If the circumstances listed above are all true and the user selects "No" so that the project will not be opened, the .xise file is overwritten with an empty one. Therefore, if the user tries to later open the project with any version of ISE software, the project cannot be opened.
This issue has been fixed in ISE 11.2. However, because ISE 11.1 has already been released, it is still possible to see the issue for users working with both ISE 11.1 and a later version.