hfss v10 v11

I have a project (*.hfss file) that I have created in HFSS v11, but I get an error when trying to open it in HFSS v10.1. Is there anyway to go between the versions?

I have parameterized the model and want to retain all the variables.

It is my understanding that you cannot open and process ver 11 files with version 10. I suspect that the solution is to redraw and re-run the model in version 10. You can however go from ver 10 to ver 11.

Is there a file format that I can export the model to and retain the features like subtractions, combines, etc? For example, will the features be retained if I export it as something like a SM3 file and then import it into HFSS v10.

It's OK for me to lose the solutions, excitations, etc. I just want to preserve the model and the features used to make it.

I would think that Ansoft would like people using old versions to be able to use their models in the new versions.