Can't open images uploaded

All of a sudden, we can’t view any images (jpg, png) that are submitted through our form. They won’t load/download in the browser, although pdfs load fine.

When trying to load in Firefox, it says it cannot be displayed because it contains errors so it sounds like something might be happening during the upload or when trying to view it from the database.

Any ideas what could cause this issue all of a sudden. We want to continue using the plugin!

https://wordpress.org/plugins/si-contact-form/