Import should always upload import file

Current Situation

An import file is corrupted and can not be uploaded. The upload ends with "Failed" and the import window is still open.

Now the corrupted import file will be fixed. When the submit button is pressed, the error still occurs. The file can not be uploaded.

Desired Behavior

When clicking the submit button in the import view, the import file always should be uploaded or the submit button should be disabled in the case of an error.