A snapshot created as part of the "Restore SnapShot" process cannot be opened for a design containing partitions.
Example
1. A design is open and a partition is placed on one or more of the source modules.
2. A snapshot (snap1) is taken of the current design (Project ->Take Snapshot).
3. Snap1 is made "current" (Project -> Make Snapshot current).
4. When prompted to save the current project as snap2, "Yes" is selected.
When I attempt to view snap1 or snap2 in the Snapshots tab, an error occurs:
"Open failed for snap2. "
Trying to make the snapshot current, fails and error occurs:
"Make Snapshot Current failed for snap2."
This problem only occurs for projects that contain partitions and if a snapshot is created while restoring an existing snapshot.
This problem has been fixed in the latest 10.1 Service Pack available at:
http://www.xilinx.com/support/download/index.htm
The first service pack containing the fix is 10.1 Service Pack 1.