Compatibility between HFSS versions

Has anyone ever experienced a compatibility problem between HFSS v12 and HFSS 11? When I try to open a v12 file with v11 it returns an I/O error. I am not sure if it is due to an error in the orginal file or to a compatibility issue.
Thanks a lot,
Alexander

As far as I know, HFSS12 projects can not be opened by previous version.

HFSS v.12 file cannot be opened with lower HFSS version v.11, saying nothing of v.10.
Moreover, v.11 file sometimes also fail to be opened with v.12, especially when model is built with variables in v.11. So I think compatibility between the high and low versions is really a bug and imperfectness of HFSS

No program promises backward compatibility. HFSS updates its ACIS versions with each release. If you open an HFSS12 file in HFSS11, it may fail due to the incompatibility of the ACIS versions. Also, if you used a new feature in HFSS12 that did not exist in HFSS11, it will fail to open as well for obvious reasons.

The fact that HFSS11 projects fail to open in HFSS12 does seem to be a bug of sorts. I would submit this with a project to your Application Engineer for resolution.

Later :)