File doesn't save properly after tried to open an invalid one

To reproduce this bug follow these steps:
1. Create a new blank BPMN or DMN file.
2. Save the file without a extension or with a invalid one.
3. Try to open the invalid file that will be listed on the home, a error message will appear.
4. Create a new blank BPMN or DMN file.
5. Save the file (can be with a valid or invalid extension).
6. The file name will still be as 'unsaved file', the home will not list the file

Expected behavior: the file should be saved and be listed on the home