Can´t import model from another .dn file into scene

Since the update it´s impossible to import models that have been created and saved in the older version of dimension into a scene. I have opened each model in Dimension and updated it to 4.0.2 and saved it since I thought it was a compatibility issue.

I´m on Macbook Pro. When I create a new scene and want to import model(s) I get the notification that Dimension needs to be restarted due to an error, I am pointed to a protocol and to post in the forum.

Since I have stupidly updated all the models, I cannot revert to an older version of dimension either to be able and get any work done.

I hope this can be fixed asap, I have tried restarting and uninstalling + reinstalling, reverting to older version etc.