Are you having problems uploading images?
You may have run into trouble uploading images to forum topics, or directly to your image library.
The old image uploader is being phased out, and will soon be replaced by the uploader that is part of the new editor.
The recommended temporary work-around is to start an instructable that you do not publish, but any images you upload to it will become available in your image library.
You may find it easier to keep that draft instructable "on file" until the uploading issue is sorted, just be careful not to accidentally publish it!