Hi Laura,
I have tried this and indeed I can save now the registration form but:
1. The values I choose in the optional fields are not saved.
2. I need at least one of this field to be mandatory.
So, I think the problem is not solved as if a user is selecting some values even if they are not mandatory they need to be saved. More, please note that this was working before. Unfortunately, I cannot tell you exactly when this changed, but I suspect it was after the upgrade on the theme to be compatible with the new BuddyPress plugin.
Thanks for checking further on this.
