Hi Pedro,

Sure, as long as the user only deleted items from the process modeler, that shouldn't have any effect on the forms themselves.  You should be able to rebuild that process as it was previously, using the forms that you've already got.  That's odd that you're getting an error message!  

Specifically, what does the error message say?  And what action is the user taking when the message pops up?  With a bit more info, we'll be able to determine if the user is doing something incorrectly, or if this is something that should be directed to our tech support team.