Hello @marco.salino! Welcome to the Community! I have a question since this on the Developer category, are you trying to import these file formats using code? If not, what is your process and what applications are you trying to use?
We may need to grab some log files to identify what the error might be. You can take a look at this post to know which log files will help us troubleshoot this issue! How to Report an issue with Omniverse