Seeing an HTTP error when uploading images in WordPress is sometimes common for users. It can be caused due to many reasons, so its essential to find the reason to troubleshoot it. Try these solutions if facing this error:
This error sometimes happens because of unusual traffic, and it will get fixed is automatically by the WordPress hosting servers.
If these solutions dont work for you, then you must check the plugins. Sometimes, a recently updated plugin can cause some error in uploading the image or any other file. So, you must proceed to disable the plugin one by one. This will help you in finding the root cause of the plugin problem.
You can also just clear your cache and browser history to fix this error. After doing this, revisit the media uploader, upload the image, and then check if the problem solved or not.