After upgrade I can no longer use class=”plain” to remove borders

Up until the latest update I was able to pick and choose which images that I did not want a border around. I have a “shop” image that I’ve used on my blogs for ages that I do not like the default border around. I was able to use: class=”plain” to remove the border from that 1 image that is in almost every post. Today after my update(which caused a lot of issues besides this) I can no longer use that tag or even img class=”noborder” to remove the border.

Any ideas? ??