Users are trying to upload heic images files into the application by using the image uploader.
Is this even possible in Mendix? If so how did you solve it?
I think that the image viewer widget and similar are limited to typical image types like JPEG and PNG. You would have to create your own HEIC-Image-Viewer widget. Can't help you with that unfortunately.
Here’s a screenshot
Can you try to convert the image to JPG and store it in the Mendix File document. Find the link below for reference.
Is there a specific issue you are running into? Mendix places no restrictions on file types: Mendix treats all files as binary data and simply stores that for later downloading. Showing HEIC files in certain browsers may be an issue, but a user can download the image and use another app to view the image.