I purchased this vertical shade less than a year ago and it was installed by Lowes. Now the slider is not opening correctly and a string is hanging from the top.

I'm sorry to hear that the shade is not operating correctly. Thank you for bringing this to our attention. Please reach out to us at 1-800-538-6567, one of our product specialists will be able to assist you. Our business hours are Monday through Friday 9:00 am to 6:00 pm eastern standard time. My apologies for any inconvenience. - Kimberly