Image source: https://wpml.org/forums/topic/http-error-when-uploading-a-new-media/

Are you seeing an 'HTTP Error' when you try to upload an image to a post? Please note that this is not related to the theme. However, you may find this thread useful in your search for a solution. This thread may also help too.

If you need any help finding a solution, please contact your web host so that they can check for the best solution on your server settings.