Can't open any file

Hi,
I’m using Visual Paradigm for school and I have made so many diagrams, bpmn models, but since a while ago none of my files will open. It says “there is no app set to open the files”.
Does anybody know how to fix this ?

Dear Ano,

Thank you for your post. Could you post a screenshot related to the problem?

Best regards,
Jick Yeung

This is what I get ( it is in Dutch by the way ).

Dear Ano,

The .vux file is not a file and you should open the .vpp file instead. To open the .vpp file, start Visual Paradigm and select Project > Open from the main menu.

Best regards,
Jick yeung