WAsP 11 and 10

No problems - WAsP 11 is able to open - in addition to WAsP 11 workspaces - WAsP 10 workspaces.

WAsP 11 and previous versions

It is not possible to open workspaces created in orlder versions of WAsP, when upgrading to WAsP 11. A solution can be to convert older projets to WAsP 10 and then open them in WAsP 11 and another solution is to purchase an additional licence instead of upgrading. This way, you will keep your dongle and thereby access to previous versions, but at the same time have access to WAsP 11 and all the new features and updates.

WAsP 9 and 10

The general rule is that WAsP workspace formats are backward compatible, i.e. e.g. WAsP 9 is able to open - in addition to WAsP 9 workspaces - also WAsP 8 workspaces and WAsP 10 is able to open - in addition to WAsP 10 workspaces - WAsP 8 and 9 workspaces.

In contrast, forward compatibility - e.g. WAsP 9 to open a WAsP 10 workspace - cannot be guaranteed.

However, you may be lucky that a WAsP10 workspace may be opened by WAsP9 under certain conditions:
- The WAsP 9 should be the latest version: WAsP 9.1.0.36,
- the workspace should only contain features supported by WAsP 9.

However, even if the above conditions are met, WAsP 9 might not be able to open the WAsP 10 workspace - so the safest thing to do is of course to upgrade to WAsP 10 when working with WAsP 10 workspaces!