From our side, we can rule out a malfunction in our image upload feature.
There are 2 different ways to upload images to hPage - have you already tried out all of them?
a.) Upload an image from PC via "Files" => "Upload files"
In the menu, click "Files" => "Upload files" and then click "Upload from this Device".
Choose the images from your PC that you would like to upload and then click on the "Upload selected files" button.
b.) Upload an image from your PC via "Editor" => "Insert image"
In the menu, click "Pages" => "Manage pages" and select the page where you want to insert an image. Click the "Insert image" button above the editor and choose the image from your PC to upload it.
Click the "OK" button and it adds your newly uploaded image on your page.
Important: In case that none of the above 2 methods work, please temporarily disable your virus scanner and firewall.