When uploading a resource, you download a "servlet" empty file

Doing the Studio training: Trainees upload a file (icon). This leads to downloading a servlet file, empty. The image is uploaded but you have to re-click the button to display the dialog and select it.

And then, you think it was not uploaded, so you re-upload etc.

This happens from anywhere in Modeler (upload logo branding, background login page, upload the Document Type's icons, ...)

Important: It happened constantly for my trainees, I had this several time in the past 3-4 weeks, but I did not have the problem myself during the training.

Major because it is poor user experience for prospects discovering Studio, knowing that changing branding is one of the first thing they do.