When you try to upload an image in WordPress you get this error:
Image has failed to upload due to an error
Unable to create directory path. Is its parent directory writable by the server?
So your images fails to upload. Maybe it was working earlier, but but now nothing succeeds in uploading. Most probably it is because of a bad configuration in Media Settings.
To fix that go to Settings > Media > Uploading Files. For the Store uploads in this folder property, put
wp-content/uploads. Your current setting may look something like
/mnt/local/home/username/website/wp-content/uploads/wp-content/uploads, replace that!
If that does not fix it, check the file permissions of WordPress files and directories. Talk to your web host, they would probably be able to help you with that.
TLDR: In Wodpress Settings > Media, set Store uploads in this folder to